Amorgianos v. National Railroad Passenger Corp., 137 F. Supp. 2d 147 (E.D.N.Y. 2001)
April 16, 2001
v.
NATIONAL RAILROAD PASSENGER CORPORATION d/b/a Amtrak, Defendant.
United States District Court, E.D. New York.
*148 *149 Lawrence P. Biondi, New York City, for plaintiffs.
Angela D. Vitali, Parker Chapin Flattau & Klimpl, New York City, for defendant.
MEMORANDUM AND ORDER
TRAGER, District Judge.
Plaintiff Nikitas Amorgianos ("Mr. Amorgianos") brought this action against the National Railroad Passenger Corporation ("Amtrak") for personal injuries allegedly suffered as a result of workplace exposure to xylene. Plaintiff Donna Amorgianos ("Mrs. Amorgianos"), his wife, joined in the action, claiming loss of consortium and services. After a jury trial and a verdict rendered in favor of plaintiffs, Amtrak moved for a judgment as a matter of law or, in the alternative, for a new trial. The court denied defendant's motion for judgment as a matter of law, but granted defendant's motion for a new trial, finding that the jury's verdict was against the weight of the evidence. Amtrak now moves to preclude plaintiffs' experts from testifying at retrial on the ground that their testimony does not meet the standard for admissibility under Federal Rule of Evidence 702 set forth in Daubert v. Merrell Dow Pharmaceuticals, Inc. and its progeny.
Background
Mr. Amorgianos is a forty-six year old man, who, until the time of the alleged accident giving rise to this action, had worked as a bridge painter since 1974. (Tr. 6/17/98, at 37-38.) Mr. Amorgianos, his wife, and his treating physician, Dr. Jacqueline Moline ("Dr. Moline"), all testified at trial that Mr. Amorgianos had been healthy prior to the incidents in question here. (Tr. 6/17/98, at 95, 129; Tr. 6/18/98, at 132.)
*150 (1)
The Steinway Street Bridge Project
On July 22, 1995, Mr. Amorgianos began working with a crew of painters employed by Romano Enterprises ("Romano"), which, along with two other painting companies, had been contracted to repaint the Steinway Street Bridge in Astoria, Queens (the "Steinway Street Bridge Project" or the "Project"). (Def.'s Letter Brief of 12/6/99, Ex. K; Tr. 6/24/98, at 40.) The Steinway Street Bridge is a street overpass for a rail line operated by defendant Amtrak. The bridge consists of three piers and two 120-foot spans; one span passes over Steinway Street, and the other passes over Twenty-Third Street. (Def.'s Letter Brief of 12/6/99, Ex. L.)
The operation involved five steps: sandblasting off the old paint; applying a primer coat; applying a white, intermediate coat; applying a red, pigmented coat; and applying an anti-graffiti top coat to the portions of the bridge visible to pedestrians. (Tr. 6/17/98, at 50; Tr. 6/24/98, at 48-49.) Different steps in this process were performed on different sections of the bridge simultaneously. (Tr. 6/24/98, at 31-33.) For instance, while one group of workers was sandblasting part of one span, another group might have been applying primer to a section of the other span.
Because the old paint was lead-based, it was necessary to enclose whichever particular section was being sandblasted in order to protect pedestrians from exposure to lead paint dust blown off the bridge. (Tr. 6/24/98, at 50.) For this purpose, a box-shaped containment consisting of tarpaulins which were fastened together was erected around the affected section of the bridge and its supporting undercarriage during the sandblasting operation. (Tr. 6/17/98, at 42, 44.) At trial, Mr. Amorgianos testified that the containment was approximately 75 to 100 feet long, (id. at 41.); Ralph P. Romano, a co-owner of Romano Enterprises, testified that it was about 100 feet long, (Tr. 6/24/98, at 47). Mr. Romano further testified that the containment was about 15 to 18 feet high and 50 feet wide, (Tr. 6/24/28, at 47).
The containment was fitted with a vacuum hose on one end to carry lead paint dust out of the interior space and into a dust collector. (Tr. 6/17/98, at 42.) There were two louvers on the wall of the containment opposite from the dust collector intake. The louvers could be opened or closed as needed to introduce fresh air into the containment and to facilitate the flow of air through it. (Id. at 44; Tr. 6/24/98, at 50-51.)
The same type of containment was used during the spray-painting phases of the operation in order to keep paint overspray from falling on pedestrians and the surrounding area. (Tr. 6/24/98, at 50.)
Romano time records indicate that Mr. Amorgianos began working on the Steinway Street Bridge Project on July 22, 1995, and continued on the job until his alleged accident on August 28, 1995. (Def.'s Letter Brief of 12/6/99, Ex. K.)
(2)
Plaintiffs' Claims
The gravamen of plaintiffs' complaint is that Mr. Amorgianos was not provided with the appropriate personal protective gear, the containment was not properly ventilated, and, as a result, he was exposed to dangerous concentrations of paint fumes while spray-painting inside the containment. Exposure to organic solvent vapors in the paint fumes, particularly xylene vapor, he contends, caused him to develop permanently disabling (1) central nervous system ("CNS") dysfunctions, such as memory loss, cognitive deficits, and changes in affect, and (2) peripheral polyneuropathy ("PN"), a neurological condition *151 involving the loss of sensation and motor control in the extremities.[1]
Specifically, plaintiffs contend that proper industrial hygienic practice is to provide a spray-painter who is working inside an enclosed space with a respirator containing a filter specially designed for organic solvent vapors. According to plaintiffs, these filters must be changed on a daily basis, or they become ineffective. Mr. Amorgianos alleges that Romano failed to provide him with an adequate supply of fresh organic vapor filters. In addition, plaintiffs contend that proper industrial hygienic practice would have been to turn the dust collector on and open the fresh air vents during spray-painting; Mr. Amorgianos alleges that this was not done on the Steinway Street Bridge Project. Plaintiffs also assert that a fan should have been placed inside the containment to increase air flow further. Plaintiffs contend that the failure to provide adequate air flow through the containment allowed dangerous levels of organic solvent vapors to accumulate within the containment, exacerbating the danger posed to Mr. Amorgianos by defendant's alleged failure to provide him with the appropriate filters for his respirator.
On the afternoon of August 28, 1995, Mr. Amorgianos became acutely ill allegedly due to his exposure to the paint fumes, left work, and has allegedly suffered disabling CNS deficits and PN since that date, with no improvement over time.
As detailed below, the various expert and non-expert factual issues raised by plaintiffs' claims were contested at trial.
(3)
The Evidence at Trial
Plaintiffs' action came for jury trial before the Honorable Edward R. Korman of this Court (the "trial judge") in June, 1998.
A. Personal Protective Gear Provided to Mr. Amorgianos
1. Plaintiffs' Evidence
When Mr. Amorgianos started on the Project, he was provided with a half-face respirator mask. (Tr. 6/17/98, at 58-60.) The respirator could be fitted with a lead dust filter and/or with a filter for organic vapors. (Id. at 59-60, 62.) The lead dust filter was to be used during sandblasting, while organic vapor filters were to be used during spray-painting. (Id.) Mr. Amorgianos testified that at certain times during his work on the Project, he sandblasted, and at other times, he spray-painted; both activities were performed inside the containment. (Id. at 59-61.)
While sandblasting, Mr. Amorgianos was also provided with a cloth hood, which covered his head and uniform. (Id. at 45.) The hood was connected to a hose that brought in fresh air from outside the containment. (Id.) Mr. Amorgianos did not, however, wear the respirator underneath the air-supplied hood during sandblasting. (Id. at 45.) Mr. Amorgianos complained that the dust collector used during sandblasting did not have enough capacity to clear adequately the air within the containment. (Id. at 43-45.)
With regard to spray-painting, Mr. Amorgianos stated that there were occasions during his first three or four weeks on the Project (i.e., from July 22, 1995 to August 11 or August 18, 1995) that he performed spray-painting work. (Id. at 59.) Mr. Amorgianos was provided with a single organic vapor filter for his respirator at that time, but was not given a replacement, and was forced to use that *152 same organic vapor filter for "a couple of weeks." (Id. at 60.) Later in the operation, he returned to spray-painting, but he was told no organic vapor filters were available, so he used only a lead dust filter for at least the last two weeks he was on the job (i.e., August 15, 1995 to August 28, 1995). (Id. at 61-62.) Mr. Amorgianos further testified that the dust collector was not turned on during spray-painting, the fresh air louvers were kept closed, and there was no fan inside the containment. (Id. at 50-53, 58.)
During Mr. Amorgianos's direct examination, plaintiffs introduced what they alleged to be the actual respirator Mr. Amorgianos was using when he became ill on August 28, 1995. (Id. at 78, 82.)[2] Mr. Amorgianos testified that he had been using that very respirator for the preceding two or three weeks, including during spray-painting. (Id. at 83.) The respirator, as introduced, contained only a lead dust filter. (Id. at 78, 83.) Mr. Amorgianos stated that he had used that particular filter for the last three days he worked. (Id. at 76.) As later noted by the trial judge, the respirator and filter were in clean, "rather pristine" condition. (Tr. 9/29/98, at 38; see also id. at 36-37 (noting that there was "not a speck of paint on the mask"), 42-45.)
Plaintiffs' expert industrial hygienist, Jack Caravanos ("Caravanos"), who testified after Mr. Amorgianos, stated on cross-examination that after one week or even one day of use, he would expect to see paint particles deposited on the lead dust filter, which is pink. (Tr. 6/18/98, at 79-80.) When shown the respirator Mr. Amorgianos allegedly used for the last two weeks of the job, Caravanos acknowledged that there was no identifiable paint residue on its exterior or on the filter. (Id. at 82, 89-91.)
On redirect, plaintiffs' counsel asked Caravanos to assume that Mr. Amorgianos had placed a T-shirt over the front of his respirator while painting, (id. at 99), though Mr. Amorgianos had given no such testimony. Plaintiffs' counsel asked whether under those circumstances Caravanos would expect to see paint materials on the respirator or filter; Caravanos answered "no." (Id. at 99-100.) Caravanos also opined that the paints Mr. Amorgianos used including those labeled "pigmented" epoxy and the third coat, which Caravanos previously testified "was a very unique color, sort of the color of maroon, so I remember it quite well," (id. at 9) might actually be colorless and that, as a result, it would only be possible to detect paint on the respirator through chemical analysis, (id. at 91, 99-100, 117-118.) Caravanos performed no chemical analysis on the respirator or filter. (Id. at 89.)
Plaintiffs subsequently called a friend of Mr. Amorgianos and a fellow painter on the Project, Nikos Kpitikos ("Kpitikos"). (See Tr. 6/23/98, at 3-4.) Kpitikos testified that the "company used to send the [organic vapor] filters [to the site] but somebody used to take it and they didn't give it to us." (Id. at 12; see also id. at 13 ("The company used to send it but nobody gave it to us. They were disappearing.").) As a result, while painting, he and the other workers would put a piece of cloth or a blouse over the front of the respirator mask. (Id. at 13-14.) Kpitikos also stated *153 that, although it was available, the workers would not use air-supplied hoods during painting because they were bulky and made maneuvering around the bridge's undercarriage difficult. (Id. at 10-12.)
In an expert report prepared after the first trial, plaintiffs' new putative expert on neurology and toxicology, Dr. Jonathan S. Rutchik ("Dr. Rutchik"), stated that Mr. Amorgianos had described his protective gear as follows: gloves, boots, a Tyvek[3] suit, a half-face mask respirator with lead dust filters, no goggles, and no hood or outside air hose. (See Def.'s Letter Brief of 12/6/99, Ex. D, at 3 (Dr. Rutchik's Expert Report).) Dr. Rutchik's report makes no mention of a practice of covering the front of the respirator with a T-shirt. (See id.)
2. Defense Evidence
Defendants called Robert Faulkner ("Faulkner"), who worked as the foreman on the Project during the week beginning August 23, 1995. (Tr. 6/23/98, at 199-200, 204-205.) Faulkner testified that during spray-painting, the painters wore air-supplied Tyvek spray hoods, respirators and organic vapor filters. (Id. at 201-02.) Faulkner stated that at no time that week were organic vapor filters unavailable and that Mr. Amorgianos never complained that he did not have one. (Id. at 202.) On Mr. Amorgianos's last day of work, Faulkner observed him coming out of the containment wearing a Tyvek suit and a respirator. (Id. at 204.)
Defendants also called John Strika ("Strika"), the chairman of the greater New York bridge painters' union. (Tr. 6/24/98, at 8-9.) Strika testified that he worked as a job steward on the Project throughout July and August 1995 (with the exception of the week of August 23-29, when he was on vacation), and that his son worked on the Project as a painter at the same time. (Id. at 9-10, 12-13, 14-15, 19-20.) Strika testified that there was a ready supply of organic vapor filters on hand at all times and that he had received no complaints from the painters that they were not available. (Id. at 11-12.) Strika did not see any painters using respirators with T-shirts wrapped around them. (Id. at 13.) However, according to Strika, the painters did not use respirators at all during painting, but instead used soft hoods with pressurized air supplies. (Id. at 21-23.) The hood was necessary to keep the paint vapors from burning the painters' eyes and to keep paint out of the painters' faces. (Id. at 27, 34-35 (explaining that the front of the hood had multiple layers of a clear cellophane-like material, which could be peeled off one by one as each became covered with paint).)
Ralph P. Romano, one of the owners of Romano Enterprises, testified that there were always organic vapor filters available on site. (Tr. 6/24/98, at 60.) Mr. Romano also testified that he visited the site on a number of occasions and would sometimes go into the containment. (Id. at 56.) On those occasions, he would wear a Tyvek suit with an air-supplied hood, but no respirator. (Id.) On such occasions during July and August 1995, he observed the painters wearing Tyvek suits and hoods. (Id. at 57.)
B. Standard Industrial Hygienic Practice
On the issue of what standard industrial hygiene required in the way of personal protective gear and ventilation on the Project plaintiffs offered the testimony of their certified industrial hygienist, Jack *154 Caravanos. Defendant called a certified industrial hygienist of its own, Frederick Toca ("Toca").
The two witnesses were in agreement that a lead dust filter (with or without a T-shirt wrapped over it) is completely ineffective at filtering organic solvents and that proper industrial hygienic practice is to provide painters working in an enclosed space with a ready supply of organic vapor filters. (See Tr. 6/18/98, at 30-31, 38 (Caravanos); Tr. 6/23/98, at 146-47, 159-60, 166 (Toca).) Neither Caravanos nor Toca testified as to whether use of an air-supplied hood without a respirator and organic vapor filter would be effective protection against organic solvent vapors.
On the issue of proper ventilation, Caravanos testified the dust collector should have been turned on, a fan should have been inside the containment, and the fresh air louvers should have been opened in order to prevent a concentration of organic solvent from accumulating inside the containment during the spray-painting operation. (Tr. 6/18/98, at 23, 27-28.) For his part, Toca was unwilling to opine on whether such ventilation was necessary without having seen how much ventilation was already available through the seams in the containment and its entryway. (Tr. 6/23/98, at 166-67, 171-73.) Toca, however, said that he would defer to the opinion of the industrial hygienist who had been contracted to inspect the site, Robert Leighton ("Leighton") of Leighton Associates, Inc. (Id. at 167-68.) Leighton separately testified that he believed that the dust collector should have been on and the air louvers opened during both sandblasting and spray-painting. (Tr. 6/22/98, at 117, 124.)
Therefore, there was no serious dispute at trial that the safety measures (or lack thereof) alleged by Mr. Amorgianos viz., use of a respirator fitted only with a lead dust filter and the absence of ventilation inside the containment would represent a departure from proper industrial hygienic practice.
C. Mr. Amorgianos's Alleged Illness
1. Direct Examination of Mr. Amorgianos
On direct examination, Mr. Amorgianos testified as follows regarding his alleged illness.
On August 28, 1995, Mr. Amorgianos started work at 7:00 a.m., stopped work at 2:30 p.m., and took two 10 minutes breaks in between. (Tr. 6/17/98, at 87.) Throughout the day, he spray-painted inside the containment, wearing only a respirator with a lead dust filter. (Id. at 87, 90.) Toward the end of the day, he began to feel dizzy. (Id. at 89.) His eyes started to close, and he felt exhausted. (Id.) When he finished working, he could not open his eyes and had to call his wife to pick him up from work. (Id. at 90.) He went home with a fever of 103 degrees. (Id.) His whole body was swollen and itchy, and his joints would not move. (Id. at 90-91.)
The next morning, August 29th, he felt worse and did not go to work. (Id. at 91.) The following day, August 30th, he showed the same symptoms and was now sweaty and had headaches. (Id.)
At that point, Mr. Amorgianos visited a neighborhood doctor, who prescribed pills for his itching and swelling. (Id. at 92.) That doctor referred to him to one Dr. Vlattas, whom he visited a week later, just after Labor Day, 1995. (Id.) At that point, his condition was not any better, he could not move from bed, and Dr. Vlattas recommended that he see an internist. (Id. at 92-93.)
Sometime in September, 1995, on Dr. Vlattas's recommendation, Mr. Amorgianos visited Dr. Moline, a board certified *155 internist and the director of the occupational medicine program at Mount Sinai Hospital in Manhattan. (Id. at 93.) Dr. Moline ordered an MRI of his brain and blood tests. (Id. at 94.) Mr. Amorgianos continued to see Dr. Moline every four to six weeks from then until the trial in June, 1998. (Id.)
Mr. Amorgianos testified that during that approximately three-year period his condition did not change, but in fact became worse. (Id.) He allegedly has no feeling in his hands, he drops things, his knees buckle beneath him, and he can no longer walk as well as he could before the exposure. (Id. at 94-95.) Every day, he gets worse. (Id.) He has no reflexes on the left side of his body, and his whole body is numb and tingly. (Id. at 95.) He can no longer do outdoor or athletic activities. (Id.)
A typical day for him as of the time of trial was to stay at home and depend on his wife for everything. (Id.) His wife must help him dress, and sometimes, he is unable to get off of the toilet by himself because his body becomes numb. (Id. at 95-96.) He is depressed and can no longer have sex or work. (Id. at 96.)
2. Cross Examination of Mr. Amorgianos
On cross-examination, Mr. Amorgianos testified that there had never been a period from August, 1995 to the trial during which he felt better. (Id. at 108.) During that time, he was able to leave the house to have dinner with his wife only "a couple of times." (Id.)
However, Mr. Amorgianos admitted that, notwithstanding his alleged condition, he had in fact vacationed in Greece two or three times during that period. (Id. at 109.) In addition, he admitted that he can and does drive a car and that he had traveled to Ohio in October 1996. (Id. at 109-110.)
While in Ohio, Mr. Amorgianos was involved in a car accident. (Id. at 110.) During the accident, he hit his head and developed a headache, so he took a taxi to the emergency room at St. Joseph Health Center in Warren, Ohio ("St. Joseph's"). (Id. at 110, 124, 125.) The emergency room notes, which were admitted into evidence, read as the follows: "The patient denies any weakness or numbness. He said his headache has improved significantly after he took ... aspirin. He denies any weakness or numbness." (Id. at 113-14 (St. Joseph's ER dictation, 10/20/96).)[4] In addition, as was revealed during cross-examination of Dr. Moline, St. Joseph's records indicate that Mr. Amorgianos was given a complete neurological workup, including a cervical spine X-ray and CT scan, all with normal results. (Tr. 6/18/98, at 143.) The records further report: (1) "Graspboth hands normal;" (2) "no sensory or motor deficit;" (3) normal reflexes in both the upper and lower extremities; (4) that Mr. Amorgianos was alert and oriented as to person, place and time; (5) a nurse's note reading "bilateral, equal, strong hand grasp, steady gait;" (6) "motor strength five over five;" (7) a normal sensory exam; and (8) "healthy" in a blank for past medical history. (Id. at 143-48.)
Nonetheless, Mr. Amorgianos testified that there have been no times since his accident that he has been able to walk normally. (Tr. 6/17/98, at 116.) Two or three blocks is the maximum that he can walk. (Id.) After that, he gets tired, and his knees buckle beneath him. (Id.)
3. The Surveillance Video
At that point in Mr. Amorgianos's testimony, the defense revealed, outside the *156 presence of the jury, the existence of a video surveillance tape taken of Mr. Amorgianos in Queens, New York on June 3, 1998. (Id. at 117-122, 141.) The tape, which was admitted into evidence and later played for the jury, shows Mr. Amorgianos driving, walking without a cane or any other type of assistance for many blocks, entering and leaving a coffee shop and a bank, all over the course of the morning and afternoon. (See Pls.' Ex. 12, received 6/22/98.) As described by the trial judge, the tape showed Mr. Amorgianos walking "much more than a quarter of a mile without any difficulty." (Tr. 9/29/98, at 69; see also id. at 34-35).
4. Mrs. Amorgianos's Testimony
Notwithstanding the surveillance video, Mrs. Amorgianos subsequently testified that her husband's condition has only become worse since August, 1995. (Tr. 6/17/98, at 132.) According to her, he cannot walk up two steps, or he will fall down. (Id.) He cannot hold a bottle of ketchup or a cup of coffee. (Id. at 132, 139-40.) He has numbness and tingling all the time and sometimes cannot get off the toilet by himself. (Id.) He cannot sleep, he sweats all night, and he cannot have sex. (Id. at 132-33.) He has not worked since August, 1995. (Id. at 134.) He cannot dress or bathe himself. (Id. at 135.) On a typical day, he gets up, has breakfast, sometimes tries to go for a walk, but gets exhausted and spends the rest of the day on the couch. (Id. at 136.)
In addition, Mrs. Amorgianos testified that her husband's emotional and cognitive functions have been impaired. According to her, Mr. Amorgianos is depressed, non-communicative and emotionless. (Id. at 134-35.) His memory is very short-term, and he cannot remember anything. (Id. at 140.)
5. Dr. Moline's Testimony
Dr. Moline was also called to testify regarding Mr. Amorgianos's medical condition. Dr. Moline stated that she had seen Mr. Amorgianos 16 or 17 times and, during that period, his symptoms have essentially remained constant. (Tr. 6/18/98, at 125.) According to Dr. Moline, he is profoundly weak, the range of motion in his joints is significantly limited, he has difficulty moving his knees, and he cannot lift his left arm. (Id. at 126, 163.)
Dr. Moline related at length what Mr. Amorgianos had told her about his condition. He reported to her that he has trouble dressing. (Id. at 163.) He has difficulty gripping a coffee cup, his arms are weak, his knees buckle when he walks, and his reflexes are gone so that he cannot break his fall. (Id.) He cannot walk for a quarter of a mile, but rather only five or six blocks. (Id. at 134, 162.) He feels constant numbness and tingling. (Id. at 127.)
Dr. Moline had a battery of tests performed on Mr. Amorgianos, including electromyography ("EMG"), nerve conduction velocity studies ("NCVS"), reflex tests and grip strength tests. The results were worse than normal, though asymmetrical in their distribution across his body: his grip strength was about ½ of what it should be in his right hand, but only 1/5 to 1/20 of what it should be in his left hand. (Id. at 128-29.) Mr. Amorgianos's "[l]eft hand was always significantly worse than [his] right." (Id. at 129.) Based on these results, Dr. Moline opined that Mr. Amorgianos was suffering from a peripheral neuropathy, permanent in nature. (Id. at 131-32.) In addition, based on the elimination of known causes of peripheral neuropathy, such as diabetes, Dr. Moline opined that Mr. Amorgianos's peripheral neuropathy was caused by his workplace exposure to organic solvents. (Id.)
*157 On cross-examination, Dr. Moline was extensively questioned about the Ohio medical records and stated that they had no effect on her opinion that Mr. Amorgianos suffers from peripheral neuropathy. (Id. at 143-49, 180.) In addition, notwithstanding Mr. Amorgianos's testimony that there has never been a time since the accident that he felt better, Dr. Moline, who had been advised by plaintiffs' counsel of the surveillance video showing Mr. Amorgianos walking throughout the course of a day, testified that sometimes Mr. Amorgianos has good days on which he is able to walk farther, and sometimes he has bad days. (Id. at 161, 164.) Finally, when questioned whether the EMG and NCVS she had performed on Mr. Amorgianos supported her diagnosis of peripheral neuropathy, Dr. Moline acknowledged that she was not personally qualified to interpret EMGs or NCVS and testified that she was relying on an interpretation of the results of those tests by a Mount Sinai physiatrist, Dr. Nahid Nainzadeh, and a Mount Sinai neurologist, Dr. Carl Bazil. (Id. at 151-155.)
6. Defense Medical Witnesses
a. Dr. Rubin
On the issue of Mr. Amorgianos's diagnosis, the defense called Dr. Michael Rubin, a neurologist. (Tr. 6/22/98, at 3.) Dr. Rubin is the director of the EMG lab and neuromuscular service at New York Hospital-Cornell Medical Center and an associate professor at Cornell University Medical College. (Id. at 6.) Dr. Rubin was retained to examine Mr. Amorgianos by an independent medical examination ("IME") provider. (Id. at 8.)[5]
Dr. Rubin examined Mr. Amorgianos on April 2, 1996. (Id. at 8.) Mr. Amorgianos reported that following exposure to epoxy paint in an enclosed space on August 28, 1995, he had suffered numbness and tingling over his whole body, though more so on the left side, as well as pain in his bones. (Id. at 9.) Mr. Amorgianos also reported that following the accident, his knees would begin to give out, and he found it difficult to walk. (Id.) Mr. Amorgianos stated that he had not had any problems prior to the August, 1995 exposure. (Id.)
Dr. Rubin conducted a physical exam and found Mr. Amorgianos's responses were "entirely normal except for sensation testing." (Id. at 10.) Dr. Rubin testified that these sensation tests are subjective, meaning that the physician simply records whatever the patient tells him or her. (Id.) Mr. Amorgianos reported decreased sensitivity to pin prick and vibration over his left arm and leg, and over his chest and abdomen. (Id.) His mental status, strength, reflexes, walking, balance and coordination were normal. (Id. at 10, 50.)
Dr. Rubin also performed an EMG and NCVS. (Id. at 10-11.) The results did not evidence peripheral neuropathy, though a single abnormal result in his left arm suggested a pinched nerve in the neck. (Id. at 11-13.) Dr. Rubin recommended that Mr. Amorgianos return to work. (Id. at 13.)
b. Dr. Budabin
The defense also called Dr. Murray Budabin. Dr. Budabin is board-certified neurologist and an associate clinical professor of neurology at Mount Sinai Hospital in Manhattan. (Tr. 6/23/98, at 56.) Dr. Budabin *158 was retained by the defense to examine Mr. Amorgianos and did so on October 7, 1997. (Id. at 58.) Mr. Amorgianos complained of weakness, numbness, tingling and joint pain. (Id. at 61.) Upon neurological examination, Mr. Amorgianos showed abnormal signs on tests that the examinee can voluntarily control, such as gait or arm strength, but on objective testing, his peripheral nerve responses were normal. (Id. at 68.) Review of an EMG and NCVS that had been performed by a Dr. Kyriakides for Dr. Vlattas, showed an abnormal results in Mr. Amorgianos's left calf muscle and in his left and right deltoids, but his NCVS was normal. (Id. at 90, 92-98, 99). Dr. Budabin testified that these results provided no evidence of peripheral neuropathy; the abnormal result for the deltoids and left calf muscle was indicative of a possible cervical radiculopathy. (Id. at 98.) According to Dr. Budabin, cervical radiculopathy most commonly results from a particular nerve in the cervical spine being compressed at its root by a herniated disc or being traumatically injured; cervical radiculopathy is not caused by exposure to toxic substances. (Id. at 101-102.) Dr. Budabin opined that based on Mr. Amorgianos's history, his physical examination, the EMG and NCVS, there was no evidence of peripheral neuropathy. (Id. at 102.)
7. Health Condition of the Other Workers on the Project
Although there were six to eight workers on the Project, (Tr. 6/17/98, at 83-85), no evidence was presented that any of the other workers suffered the type of permanent illnesses Mr. Amorgianos alleges.
D. Causation Testimony
1. Caravanos
Plaintiffs presented Caravanos, a certified industrial hygienist, on, inter alia, the issue of causation. (Tr. 6/18/98, at 3.) Caravanos holds a B.S. in Environmental Health Science from the City University of New York, an M.S. in Environmental Health from Brooklyn Polytechnic Institute, and a Doctorate in Public Health from Columbia University. (Id. at 2.) He is the chairman of the Hunter College industrial hygiene program and also serves as an adjunct assistant professor at Robert Wood Johnson Medical School of the University of Health and Dentistry of New Jersey. (Id. at 4, 6.)
Caravanos testified that because the enclosure in which Mr. Amorgianos worked was airtight and the fresh air louvers were kept closed during spray-painting, paint fumes accumulated within the enclosure. (Id. at 12.) These fumes consisted of vapor from the organic solvents of which the paint products used on the Project were partly composed. (Id. at 25.) Caravanos opined that the concentration of these vapors within the containment had reached dangerous, life-threatening levels. (Id. at 23-24.) Specifically, Caravanos opined that, based on his calculations of the amounts of paint used, the volume of the containment, and the amounts of organic solvents within the paint products, the concentration of a particular organic solvent, xylene, was in the "thousands" of parts per million ("ppm"). (Id. at 40-41.) Caravanos further testified that the Occupational and Safety Administration ("OSHA") has promulgated a personal exposure limit ("PEL") for xylene of 100 ppm. (Id. at 41.)[6] Caravanos opined that Mr. Amorgianos's *159 exposure to a concentration of xylene in excess of the OSHA PEL, without the protection of a respirator fitted with an organic vapor filter, was the likely cause of Mr. Amorgianos's alleged illness. (Id. at 52-53.)
On cross-examination, Caravanos admitted that he did not have a medical degree. (Id. at 59.) His opinion that exposure to xylene at levels he estimated caused Mr. Amorgianos's particular set of symptoms was based on a literature search on medical databases. (Id. at 60.) Specifically, he searched MEDLINE and TOXLINE for the key words "xylene poisoning in painters" and found hundreds of references. (Id. at 110-11.) So, he "just printed the first 50." (Id. at 111.) When asked whether he read the referenced articles themselves, Caravanos stated that he had "read some of the abstracts." (Id. at 111.) At that point, the trial judge ordered that his testimony on causation be stricken as incompetent in light of his failure to read any of the articles and the fact that he is not an epidemiologist. (Id. at 112-16.)
2. Dr. Moline
Dr. Moline testified briefly that she believed to a reasonable degree of medical certainty that Mr. Amorgianos's exposure to organic solvents on the Project caused his peripheral neuropathy, based on the chemicals to which he was exposed, the timing of the onset of his illness, his manifestation of symptoms described in the medical literature on organic solvents, and her elimination of known causes of PN, such as diabetes. (Id. at 132-33.)
3. Dr. Budabin
Dr. Budabin was not questioned at length on the issue of causation, but he testified that exposure to toxic substances would not cause a neuropathy that was asymmetrical in nature, except if one were to place one's hand into a toxic substance. (Tr. 6/23/98, at 69.) Dr. Budabin testified that since other types of chemical exposure (such as inhalation) have a systemic effect, any resulting neuropathy would be equal in both sides of the body. (Id.) Such an effect would stand in contrast to Mr. Amorgianos's alleged symptoms, which were allegedly much worse on the left side of his body than the right. (Id.)
(4)
The Verdict
On June 26, 1998, the jury returned a verdict for plaintiffs in the amount of $2.3 million after adjusting for its finding that Mr. Amorgianos was comparatively 30% at fault.
(5)
Post-Trial Proceedings
On August 7, 1998, defendant moved for judgment as a matter of law or, in the alternative, for a new trial.
On September 29, 1998, the trial judge denied defendant's motion for judgment as a matter of law, but granted its motion for a new trial, finding that the verdict was "fundamentally against the overwhelming weight of the evidence" and represented a "miscarriage of justice." (Tr. 9/29/98, at 67.) The trial judge based his decision on a number of factors, including:
(1) the video surveillance tape, which showed Mr. Amorgianos walking "much more than a quarter of a mile without any difficulty," (id. at 69; see also id. at 34-35);
(2) the Ohio medical records related to Mr. Amorgianos's car accident, which showed a normal neurological exam and in which he reported none of the symptoms claimed in the present action, (see id. at 35, 68-69, 71-72);
(3) defense neurologists had testified that the effects of toxically-induced peripheral *160 neuropathy typically present in an symmetrical pattern, but plaintiff's alleged peripheral neuropathic illness was asymmetrical, (see id. at 36, 64, 68);
(4) the absence of any paint residue on the respirator plaintiff allegedly used on the Steinway Street Bridge Project, and plaintiff's failure to produce any plausible explanation for its "rather pristine" condition, (see id. at 36-38, 42-45); and
(5) the deficiencies in plaintiffs' medical evidence, including the fact that Caravanos had offered an opinion on general causation based only on a review of article abstracts and not the articles themselves, (see id. at 38, 51); and doubts as to the credibility of Dr. Moline's trial testimony, (see id. at 54, 72-73).
The trial judge expressly noted that his decision was not based on any one of these factors considered in isolation but rather on the cumulative effect of all of them taken together. (See id. at 45, 69-70.)
At plaintiffs' request, this case was reassigned to the undersigned judge for retrial. Subsequently, plaintiffs retained a new putative expert on neurotoxicology, Dr. Jonathan S. Rutchik, and defendant retained a new toxicology expert of its own, Dr. Jack W. Snyder.
After the completion of additional expert discovery, defendant moved to preclude plaintiffs' expert witnesses on the ground that their opinions were not sufficiently reliable under the standards set forth in Daubert v. Merrell Dow Pharmaceuticals, Inc. and its progeny.
Discussion
(1)
Under New York law, when the determination of whether an illness or injury was caused by some event or conduct is "presumed not to be within common knowledge and experience," a plaintiff must produce expert opinion evidence "based on suitable hypotheses" in order to support a finding of causation. Meiselman v. Crown Heights Hosp., 285 N.Y. 389, 396, 34 N.E.2d 367, 370 (1941); see Fane v. Zimmer, Inc., 927 F.2d 124, 131 (2d Cir. 1991).
As a threshold matter, it must be noted that this is not a case in which the burden-shifting analysis announced in Martin v. Herzog, 228 N.Y. 164, 126 N.E. 814 (1920), applies. In Martin v. Herzog, Judge Cardozo held that there is prima facie evidence of a causal link between an offending party's negligence and a victim's injury where the offending party violates an ordinance enacted to protect human safety and the victim suffers the very type of injury the ordinance was designed to protect against. See Martin v. Herzog, 228 N.Y. at 170, 126 N.E. at 816; see also Valencia v. Lee, 123 F. Supp. 2d 666, 685-86 (E.D.N.Y.2000) (applying New York law) (shifting burden on causation where infant plaintiff, who had blood lead levels above limit established by federal and municipal health agencies, developed learning disabilities). Here, it will be assumed for the purpose of deciding this motion that Mr. Amorgianos was exposed to xylene in concentrations in excess of the 100 ppm PEL or the 150 ppm short-term exposure limit ("STEL") promulgated by OSHA. Mr. Amorgianos's alleged illness, however, is not of the type that the OSHA PEL and STEL for xylene were promulgated to protect against. In the release notes accompanying its promulgation of the xylene PEL and STEL, OSHA stated that it adopted the xylene PEL and STEL to protect workers against three specific adverse health effects: (1) narcosis; (2) eye irritation; and (3) adverse serologic effects. See Air Contaminants, 54 Fed.Reg. 2332, 2477 (1989) (final rule amending 29 C.F.R. § 1910.1000). The 1989 release notes which post-date most of the research *161 cited by plaintiffs' experts, see infra Appendix tbls. 1-3 do not recite chronic CNS or PNS effects as a justification for the adopted PEL or STEL. See id. Thus, even if one assumes that Caravanos's estimate of the concentration of xylene within the containment is correct, plaintiffs are not entitled to shift the burden of proof on causation to defendant under the rule of Martin v. Herzog based on the alleged violation of the OSHA exposure limits.
Accordingly, this case presents five distinct issues on which plaintiffs must produce admissible expert opinion evidence:
(1) What does standard industrial hygienic practice require in the way of personal protective gear and ventilation for the type of spray-painting operation conducted during the Steinway Street Bridge Project?;
(2) Is plaintiff ill, and, if so, what is his diagnosis?;
(3) To what dose of xylene or other organic solvents was plaintiff exposed while on the Project, and for what duration?;
(4) Can exposure to xylene (or the other organic solvents contained in the paint products with which plaintiff worked) in the amount and for the duration experienced by plaintiff cause an individual to develop the particular complex of CNS and PNS symptoms that plaintiff allegedly suffers?; and
(5) Was plaintiff's exposure to xylene (and other organic solvents) the specific cause of his alleged development of these CNS and PNS symptoms?
The issue presented by question (4) is commonly referred to as that of "general causation," and that presented by question (5) as "specific causation." See Mancuso v. Consolidated Edison Co. of N.Y., 56 F. Supp. 2d 391, 394-95 (S.D.N.Y.1999), aff'd in relevant part, 216 F.3d 1072, 2000 WL 730417 (2d Cir.2000) (Table).
Plaintiffs have proffered Dr. Moline, Caravanos, and a new putative expert on toxicology and neurology, Dr. Jonathan S. Rutchik ("Dr. Rutchik"), to testify on these questions. Defendant has moved to exclude the testimony of these witnesses on questions (3) and (4), on the ground that their opinions as to the dose and duration of Mr. Amorigianos's exposure to xylene and on general causation are not sufficiently reliable to meet the standards for admissibility under Federal Rule of Evidence 702 set forth in Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, 113 S. Ct. 2786, 125 L. Ed. 2d 469 (1993), and its progeny.[7]
*162 Effective December 1, 2000, Rule 702 provides:
If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion or otherwise, if (1) the testimony is based upon sufficient facts or data, (2) the testimony is the product of reliable principles and methods, and (3) the witness has applied the principles and methods reliably to the facts of the case.
Fed.R.Evid. 702.[8] The proponent of expert evidence under Rule 702 must establish its admissibility by a preponderance of the evidence. See id. adv. committee note (2000 Amendments) (citing Bourjaily v. United States, 483 U.S. 171, 107 S. Ct. 2775, 97 L. Ed. 2d 144 (1987)); Daubert, 509 U.S. at 592 n. 10, 113 S. Ct. at 2796 n. 10.
A. Daubert
In its landmark decision in Daubert, the Supreme Court established a two-prong test for admissibility of expert scientific testimony: the testimony must (1) relate to "scientific knowledge" and (2) "assist the trier of fact to understand or determine a fact in issue." 509 U.S. at 592, 113 S. Ct. at 2796. The Court described the first requirement as one of "evidentiary reliability," and the second as one of "fit." Id. at 589-92, 113 S. Ct. at 2795-96.
In assessing the reliability of a proffered expert's testimony, a district court's inquiry under Daubert must focus, not on the substance of the expert's conclusions, but on whether those conclusions were generated by a reliable methodology. See id. at 590, 595, 113 S. Ct. at 2795, 2797. To assist district courts in making this preliminary assessment, the Court enumerated four non-exclusive factors for determining whether an expert opinion is reliable: (1) whether the expert's conclusions have been tested or are testable; (2) whether the expert's conclusions have been published and subjected to peer review; (3) in the case of a scientific technique, the potential or known error rate; and (4) whether the expert's conclusions have gained general acceptance in the relevant scientific community. See id. at 593-94, 113 S. Ct. at 2796-97.
The courts of appeals have applied other factors as well, such as whether the theory or method offered by the expert has been put to any non-judicial use, see Cabrera v. *163 Cordis Corp., 134 F.3d 1418, 1420-21 (9th Cir.1998); In re Paoli R.R. Yard PCB Ligit., 35 F.3d 717, 742 n. 8 (3d Cir.1994), "or whether they have developed their opinions expressly for purposes of testifying," Daubert v. Merrell Dow Pharms., Inc., 43 F.3d 1311, 1317 (9th Cir.1995) ("Daubert II").
Additional factors may be appropriate in a given case, and a district court enjoys the same "broad latitude" in deciding what are the "reasonable measures of reliability in a particular case" as it does in reaching its ultimate determination of reliability. Kumho Tire, 526 U.S. at 142, 153, 119 S. Ct. at 1171, 1176. Rule 702's standard of reliability is, however, "exacting," Weisgram v. Marley Co., 528 U.S. 440, 455, 120 S. Ct. 1011, 1021, 145 L. Ed. 2d 958 (2000), and does not, as some pre-Daubert courts held, turn simply on the quality of the proffered expert's credentials. Compare, e.g., Ferebee v. Chevron Chem. Co., 736 F.2d 1529, 1534 (D.C.Cir.1984) ("On questions such as these, which stand at the frontier of current medical and epidemiological inquiry, if experts are willing to testify that such a link exists, it is for the jury to decide whether to credit such testimony."), with Fed.R.Evid. 702 adv. committee note (2000 Amendment) ("The trial court's gatekeeping function requires more than simply `taking the expert's word for it.'" (quoting Daubert II, 43 F.3d at 1319)).
Daubert's second criterion of "fit" is essentially a requirement of relevance: "Rule 702's `helpfulness' standard requires a valid scientific connection to the pertinent inquiry as a precondition to admissibility." Daubert, 509 U.S. at 591-92, 113 S. Ct. at 2796. A proffered expert opinion may fail to meet the fit requirement if it relates to "facts or data that have not been adequately established in the case." Fed. Jud. Ctr., Reference Manual on Scientific Evidence 47 (1994); see Fed.R.Evid. 702 (as amended) (providing that expert opinion is admissible if "based upon sufficient facts or data"). Thus, "[e]ven if an expert testifies that Substance X can cause the plaintiff's injury, this testimony will not suffice if the plaintiff failed to produce evidence that he or she was exposed to Substance X ... or at a significant level." Id. at 48. Similarly, where there is expert testimony that a given substance can cause a certain condition, but an exposed plaintiff complains of a different condition, the expert's opinion, even if reliable, does not fit the facts of the case, is not helpful to the trier of fact, and, thus, is inadmissible.
Accordingly, in a toxic tort case, expert testimony on the issue of general causation meets Daubert's "fit" requirement only if the testimony includes an opinion that (1) exposure to the particular substance at issue, (2) in the dose to which the plaintiff was exposed, (3) for the duration in which plaintiff was exposed, (4) can cause the particular condition(s) of which the plaintiff complains.
B. Application of Daubert to Expert Testimony Based on a Review of Existing Medical Literature
Plaintiffs' experts have done no research of their own on the question of whether exposure to xylene or the other organic solvents to which Mr. Amorgianos was allegedly exposed in the amount and for the duration claimed by plaintiffs can cause the crippling peripheral neuropathy and CNS effects Mr. Amorgianos allegedly suffers. Instead, their methodology consists of an extrapolation from existing medical evidence on the relationship between exposure to various organic solvents and various PNS and CNS conditions, buttressed by the temporal proximity of the onset of Mr. Amorgianos's alleged illness to his alleged exposure to xylene and other organic *164 solvents on the Steinway Street Bridge Project.
Fortunately, in Joiner, the Supreme Court provided substantial guidance on the proper assessment of the reliability of expert testimony that is based on extrapolation from the findings of existing medical studies. Because there is conflicting Second Circuit authority on this issue,[9] an extended examination of the Supreme Court, court of appeals, and district court opinions in Joiner is necessary to ascertain the appropriate standards to be applied to this motion.
1. Joiner in the District Court
In Joiner, a plaintiff electrician who suffered from lung cancer alleged that he had been exposed to a dielectric cooling fluid which was contaminated with PCBs and other toxins in the course of his work with electrical transformers. Joiner proffered three experts who relied on epidemiological and animal studies to conclude that this exposure to PCBs had caused, or at least promoted, his subsequent development of lung cancer.
After conducting a searching review of the data relied on by Joiner's experts, the district court found that: (1) the authors of some of the epidemiological studies expressly stated that they had found no statistically significant association between PCBs and lung cancer; (2) the other epidemiological studies either did not mention PCBs or involved confounding factors, such as exposure to other toxins, and (3) the experimental studies on mice involved a different type of cancer than that suffered by the plaintiff. See Joiner v. General Elec. Co., 864 F. Supp. 1310, 1322-26 (N.D.Ga.1994), rev'd, 78 F.3d 524 (11th Cir.1996), rev'd, 522 U.S. 136, 118 S. Ct. 512, 139 L. Ed. 2d 508 (1997). Stating that it was not persuaded that "th[ose] studies support the `knowledge' the experts purport to have," the district court excluded the testimony of all three experts and granted summary judgment to the defendant manufacturer. See id. at 1326.
2. Joiner in the Court of Appeals
On appeal, the Eleventh Circuit reversed, holding that the district court's criticisms of the plaintiff's expert testimony went to the testimony's weight, rather than its admissibility. The court of appeals began by noting that the district court's evidentiary review was at odds with the "`liberal thrust'" of Daubert, 509 U.S. at 588, 113 S. Ct. at 2794 (quoting Beech Aircraft Corp. v. Rainey, 488 U.S. 153, 169, 109 S. Ct. 439, 450, 102 L. Ed. 2d 445 (1988)), and the Federal Rules of Evidence:
It is important for trial courts to keep in mind the separate functions of judge and jury, and the intent of Daubert to loosen the strictures of Frye and make it easier to present legitimate conflicting views of experts for the jury's consideration.
Joiner, 78 F.3d at 530. The Eleventh Circuit then strongly criticized the district court for excluding "the testimony because *165 it drew different conclusions from the research than did each of the experts," and admonished that under Daubert, a district court should not "make independent scientific judgments on the basis of individual studies":
[T]he gatekeeping responsibility of the trial courts is not to weigh or choose between conflicting scientific opinions, or to analyze and study the science in question in order to reach its own conclusions from materials in the field.
Id.; see also id. ("[Daubert] is not intended to turn judges into jurors or surrogate scientists."); cf. Maiorana, 52 F.3d at 1137 (warning that "the law does not `impose[] on [judges] either the obligation or the authority to become amateur scientists'" (quoting Daubert, 509 U.S. at 601, 113 S. Ct. at 2800 (Rehnquist, C.J., concurring in part and dissenting in part))).
On this latter point, Judge Birch specially concurred:
Whether the conclusions advanced from the stated premises in fact follow and the persuasiveness of those conclusions in the ultimate resolution of competing opinions, are questions appropriately left to the finder of fact.
Joiner, 78 F.3d at 534-35 (Birch, J., specially concurring); cf. Maiorana, 52 F.3d at 1126, 1131, 1133, 1139 (in scrutinizing the studies relied on by expert, district court improperly "substituted its judgment for that of the jury").
Finally, reviewing the criticisms leveled by the district court against plaintiff's experts, the Eleventh Circuit held: "None of these reasons is sufficient to render an expert's opinion legally unreliable." Joiner, 78 F.3d at 532. The Eleventh Circuit, therefore, reversed the district court's exclusion order, stating the "tests and criticisms cross-examination would supply," were the proper device for treating such deficiencies in expert testimony. Id.; cf. Maiorana, 52 F.3d at 1132 (district court's criticisms of expert's testimony went to weight and should have been dealt with through "the traditional devices of `[v]igorous cross-examination, presentation of contrary evidence, and careful instruction on the burden of proof'" (quoting Daubert, 509 U.S. at 596, 113 S.Ct. at 2798)).
3. Joiner in the Supreme Court
In an eight-to-one decision authored by Chief Justice Rehnquist, the Supreme Court squarely rejected the Eleventh Circuit's reasoning and held that the district court's analysis was entirely proper under Daubert. The Court clarified that it is "within a District Court's discretion to conclude that the studies upon which the experts rel[y][are] not sufficient, whether individually or in combination, to support their conclusions" on causation. Joiner, 522 U.S. at 146-47, 118 S. Ct. at 519.[10] After reiterating that Daubert requires district courts to screen out unreliable expert testimony, see id. at 142, 118 S. Ct. at 517, the Court conducted an illuminating step-by-step review of the district court's analysis of the studies relied upon by Joiner's experts.
Agreeing with the district court at each step, the Court placed special emphasis on the fact that the authors of two of the epidemiological studies relied on by the plaintiff's experts were unwilling to conclude that those studies established a causal link between PCB's and lung cancer. See id. at 145, 118 S. Ct. at 518 ("Given that *166 Bertrazzi et al. were unwilling to say that PCB exposure had caused cancer among the workers they examined, their study did not support the experts' conclusion that Joiner's exposure to PCBs caused his cancer."); id. at 145, 118 S. Ct. at 519 (noting that increased incidence of lung cancer found in second study "was not statistically significant and the authors of the study did not suggest a link between the increase in lung cancer deaths and the exposure to PCBs"). The Court upheld the district court's rejection of the two remaining epidemiological studies on grounds of "fit": one was limited to a particular kind of mineral oil and did not mention PCBs; the other involved PCB-exposed workers who had also been exposed to numerous other potential carcinogens. See id. at 145-46, 118 S. Ct. at 519.
In another significant illustration of the "fit" requirement, the Court also rejected the animal studies upon which Joiner's experts relied. The Court noted that the studies in question involved infant mice that had developed alveologenic adenomas after massive doses of PCBs were injected directly into their stomachs and peritoneums; Joiner, however, suffered from small-cell carcinoma, an entirely different disease. See id. at 144, 118 S. Ct. at 518. Explaining that the "issue was whether these experts' opinions were sufficiently supported by the animal studies on which they purported to rely," the Court held that "[t]he studies were so dissimilar to the facts presented in this litigation that it was not an abuse of discretion for the District Court to have rejected the experts' reliance on them." See id. at 144-45, 118 S. Ct. at 518.
Most significantly, the Supreme Court definitively rejected the Eleventh Circuit's reasoning that a point-by-point examination of the data relied on by experts runs afoul of Daubert's admonition that a district court's "focus ... must be solely on the principles and methodology, not the conclusions they generate," Daubert, 509 U.S. at 595, 113 S.Ct. at 2797:
Conclusions and methodology are not entirely distinct from one another. Trained experts commonly extrapolate from existing data. But nothing in either Daubert or the Federal Rules of Evidence requires a district court to admit opinion evidence which is connected to existing data only by the ipse dixit of the expert. A court may conclude that there is simply too great an analytical gap between the data and the opinion offered. That is what the District Court did here, and we hold that it did not abuse its discretion in so doing.
Joiner, 522 U.S. at 146, 118 S. Ct. at 519 (emphasis added) (citing Turpin v. Merrell Dow Pharms., Inc., 959 F.2d 1349, 1360 (6th Cir.1992) ("The analytical gap between the evidence presented and the inferences to be drawn on the ultimate issue of [causation] is too wide. Under such circumstances, a jury should not be asked to speculate on the issue of causation.")).
4. Subsequent Second Circuit Authority
A recent Second Circuit decision confirms the bounds of a district court's discretion to exclude unreliable expert evidence as announced in Joiner. See Washburn v. Merck & Co., 213 F.3d 627, 2000 WL 528649 (2d Cir.2000) (Table). In Washburn, the plaintiff's experts opined that the defendant's rubella vaccine had caused her to develop arthropathy, arthralgia and chronic fibromyalgia. The Second Circuit upheld the exclusion of the plaintiff's experts and the granting of summary judgment to the vaccine manufacturer, where the experts' opinions were based "on little more than temporal correlation between [the plaintiff's] vaccination and the onset of symptoms." Id., *167 213 F.3d 627, 2000 WL 528649, at *2 (citing Cavallo v. Star Enter., 892 F. Supp. 756 (E.D.Va.1995), aff'd in relevant part, 100 F.3d 1150 (4th Cir.1996); Conde v. Velsicol Chem. Corp., 804 F. Supp. 972, 1023 (S.D.Ohio 1992), aff'd, 24 F.3d 809 (6th Cir.1994)). In particular, the Second Circuit rejected one expert's extrapolations from the medical literature as unreliable where, inter alia, (1) those studies explored a link between the vaccine and arthritis, rather than the specific chronic joint conditions alleged by the plaintiff, and (2) even "the evidence linking the vaccine with arthritis [was] derived mainly from anecdotal reports and small population studies with few controls." Id. Another of plaintiff's expert's opinion on causation was ruled to have been properly rejected where it "did not emanate from his own research in the field, but rather was developed for the purposes of litigation.... [The district court] reviewed the studies and articles that [the expert] used to conclude that there is a causal relationship between [the defendant's vaccine] and chronic joint conditions and found that none was a large-scale epidemiological study and most were either anecdotal, or did not involve [the defendant's vaccine]." Id. Earlier Second Circuit decisions that suggest such an examination of the authorities relied upon by a plaintiff's experts oversteps the bounds of a district court's discretion under Daubert, e.g., Maiorana, 52 F.3d at 1133, 1137, 1139,[11] therefore, no longer appear vital in the wake of Joiner.
5. Relevant Epidemiological Principles
In addition, in assessing whether plaintiffs' experts have reliably extrapolated their causal hypothesis from the existing medical evidence and the significance of temporal proximity of plaintiff's alleged exposure and illness, the fundamental principles of epidemiology, which are now becoming well known to the courts, provide additional guidance.
There are several different forms that epidemiological studies take in the areas of occupational medicine and toxicology. These various research designs differ in the evidentiary weight they lend to a hypothesis that exposure to a given substance causes a given condition. See Environmental & Occupational Medicine 44 (William N. Rom ed., 3d ed.1998) (cited by Dr. Rutchik as authoritative); Reference Manual, supra, at 131-38. The epidemiological studies cited by plaintiffs' experts fall into two general categories: (1) uncontrolled case studies or case reports; and (2) cross-sectional studies. See infra Appendix tbls. 1-3.[12]
"An uncontrolled case study, or case-series report, is not actually a formal epidemiologic investigation but simply the identification of an unusual occurrence or disease." Rom, supra, at 44. The principal function of such reports is to alert health professionals to the possibility of occupational causes of disease. See id. at 45. "In an occupational cross-sectional study, a survey is conducted to determine *168 and compare the prevalence of disease or health status between groups of workers classified with respect to exposure status." Id. One of the main limitations of cross-sectional studies is that they are confined to actively employed workers who have chosen to participate; "[w]orkers who have left employment for reasons that might be related to exposure and those who choose not to participate are excluded." Id.
Because of their inherent limitations, these two study designs "usually represent preliminary or pilot investigations used to screen for possible workplace hazards or to generate hypotheses for testing in more complex designs." Id. at 44. In contrast, cohort studies, which test for the incidence of a health condition in a randomly selected group of exposed workers and a randomly selected group of unexposed workers over time, see id. at 46-47, and case-control studies, which compare the exposure histories of a group of workers who exhibit a particular health condition with a group of workers who do not exhibit the health condition but who are comparable in characteristics other than exposure, see id. at 47-49, are "the most informative investigations used to test specific etiological hypotheses and to confirm and quantify degrees of health risk related to causal exposures," id. at 44. Notably, none of the epidemiological studies cited by plaintiffs' experts was a cohort or case-control study. See infra Appendix tbls. 1-3.
Even when an appropriately designed study yields evidence of a statistical association between a given substance and a given health outcome, epidemiologists generally do not accept such an association by itself as proof of a causal relationship between the exposure and the outcome. See Rom, supra, at 50; Casarett & Doull's Toxicology 79 (Curtis D. Klaassen ed., 5th ed.1996) (cited by Dr. Rutchik as authoritative). Epidemiologists generally look to several additional criteria to determine whether a statistical association is indeed causal. See id. These criteria are sometimes referred to as the Bradford Hill criteria, after the author of a leading statement of the principles. They are:
(1) Strength: How strong is the association between the suspected risk factor and the observed outcome?;
(2) Consistency: Does the association hold in different settings and among different groups?;
(3) Specificity: How closely are the specific exposure factor and the specific health outcome associated? I.e., how unique is the quality or quantity of the response?
(4) Temporality: Does the hypothesized cause precede the effect?;
(5) Biological plausibility: Does the apparent association make sense biologically?;
(6) Coherence: Is the association consistent with what is known of the natural history and biology of the disease?;
(7) Experimental verification: Does any experimental evidence support the hypothesis of an association?;
(8) Biological analogy: Are there examples of similar risk factors and similar outcomes?; and
(9) Dose-response relationship: Has a dose-response relationship been established, i.e., does the magnitude of the response increase as the magnitude of the dose increases? See Rom, supra, at 50-51; Casarett & Doull's, supra, at 79; Reference Manual, supra, at 160-164. The last criterion, establishment of a dose-response relationship, is considered critical in toxicology. See Casarett & Doull's, supra, at 18.
(2)
The toxicity of any substance depends critically on the dose to which a human being is exposed and for what duration. *169 See Reference Manual, supra, at 185; Expert Evidence 124 (Bert Black & Patrick W. Lee eds., 1997); (Rutchik Dep. at 301). Thus, in order for the jury to evaluate the hypothesis that Mr. Amorgianos's alleged illness could be caused by his level of exposure to xylene or other organic solvents, plaintiffs must establish what that exposure was in terms of dose and duration. On the question of dose, plaintiffs have profered Caravanos; on the question of duration, plaintiffs have profered Caravanos and Dr. Rutchik. For the reasons that follow, plaintiffs' experts' opinions as to dose and duration are excluded.
A. Dose
1. How should dose be measured?
As an initial matter, it must be determined how dose should be measured in the circumstances of this case. Plaintiffs contend that it is appropriate to measure dose in terms of the ambient concentration of xylene vapor within the containment, and they have offered an estimate by Caravanos as to what the concentration was. Defendant, however, strenuously argues that it is an individual's absorption of a chemical that determines what effect the chemical will have on his body, and that estimates of dose (and, therefore, causal hypotheses about the effect of a chemical) must be given in terms of the amount of the chemical actually absorbed by the individual. Defendant further argues that the concentration of a chemical in the air breathed by an individual cannot serve as a proxy for the amount absorbed, because different individuals exposed to a given ambient concentration of xylene may absorb different amounts of xylene into their bodies as a result of their individual physiologies. Defendant then observes that none of plaintiffs' experts have given any estimate of the amount of xylene absorbed by Mr. Amorgianos and conclude that no causal opinion based on ambient concentration alone can be found to "fit" the evidence in this case.
As plaintiffs aptly put it, defendant's argument is a red herring. Virtually all of the studies submitted by plaintiffs, see infra Appendix tbls. 1-3, that describe dose at all, describe it in terms of the ambient concentration of the organic solvent in question, and it, therefore, appears that it is accepted practice in epidemiology and toxicology to measure dose in terms of ambient concentration in cases, such as those considered in these studies, where the study subjects' actual body burdens of the chemical in question have not or cannot be measured at the time of exposure. See generally Rom, supra, at 40 ("In most cases, doses and dose rates cannot be measured directly, and surrogate measures must be developed from data on exposures observed in the environment external to the worker. Exposure concentration or intensity is used as a surrogate for dose rate...."). While it may well be that different individuals absorb xylene and other chemicals at different rates, those absorption rates presumably fall into some well-defined distribution. As a result, the statistical results of studies involving large numbers of subjects will not be affected by such individual variations in absorption rate. Thus, such data does appear to be an accepted and acceptable basis for epidemiological hypothesis testing.
Moreover, defendant's insistence that plaintiffs should be required to demonstrate the actual amount of a chemical in a plaintiff's body would, in most cases, place an impossible burden on workers injured as the result of workplace exposure to toxic chemicals. The half-life of a given chemical in a person's blood may be only a few days or weeks, and the focus of a physician who treats a worker who has fallen ill on the job will be on the assessment *170 and treatment of the worker's illness, not on a forensic inquiry into the possible toxicological causes of the illness.[13] Consequently, in many, if not most, cases of illness related to workplace exposure to toxic chemicals, the tests necessary to determine the information that defendant demands will not be performed when the worker becomes ill, and, by the time such a worker initiates litigation, such tests will not be able to produce any useful information. Therefore, defendant's argument that a causal hypothesis that is framed in terms of ambient concentration will not generally meet Daubert's "fit" requirement must be rejected as contrary to both accepted epidemiological practice and sound legal policy.[14]
2. Caravanos's Opinion on Concentration
As far as the record reveals, no measurement of the concentration of xylene within the containment was ever made. Therefore, the concentration of xylene within the containment can only be estimated based on the amount of paint used, its xylene content, the volume of the containment and other environmental factors.
Plaintiffs have proffered Caravanos on the issue of concentration.[15] Caravanos, *171 who has authored a textbook on quantitative industrial hygiene used at a number of universities, (Tr. 6/18/98, at 7), performed a number of calculations prior to trial to arrive at an opinion on concentration, which he expressed at trial only by testifying that the concentration of xylene was in the "thousands" of parts per million ("ppm"), (id. at 40-41). After the trial, Caravanos revised his calculations, which come to the court in the form of a synopsis contained within Dr. Rutchik's expert report, and a graph and spreadsheets Caravanos supplied to Dr. Rutchik, which were introduced as exhibits at Dr. Rutchik's deposition. (Def.'s Letter Brief of 12/6/99), Ex. C (graph and spreadsheets); id. Ex. D, at 12 (Dr. Rutchik's Expert Report) (summarizing Caravanos's opinion on concentration). Caravanos's current opinion is that on days that spray-painting was performed within the containment, the xylene concentration increased in a linear fashion over the course of the workday from zero to 2,000 ppm. (See id.) Given the change in the concentration of xylene, so calculated, Caravanos now opines that at any given time Mr. Amorgianos was spray-painting he was exposed to a concentration of 500 to 2,000 ppm of xylene. (See id.)
Caravanos's calculations are simple and straightforward. Caravanos multiplied an estimate of the amount of paint used on an average workday by the percentage of xylene within the paint (as thinned) to arrive at an estimate of the amount of xylene released into the containment on an average workday. (Caravanos Dep. at 100-01.) Caravanos then divided the amount of xylene released by the volume of the containment to arrive at the concentration of xylene within the containment. (Id.) Caravanos assumed that the paint was applied and that xylene evaporated from the paint at a constant rate throughout the workday, and that all of the xylene in the paint had evaporated into the air by the end of the workday, where it remained sealed within the containment, which he assumed for the purposes of calculation was airtight. (Caravanos Dep. at 128-29, 141; Def.'s Letter Brief of 12/6/99, Ex. C (graph).)
There are a number of problems with Caravanos's calculations and his resulting opinion on concentration in terms of the evidentiary support (or lack thereof) for his underlying assumptions and in terms of whether he reliably applied his stated methodology. Some of these problems go to his opinion's weight and thus are properly tested on cross-examination. But others go to its reliability and, hence, its admissibility.
Before proceeding to an analysis of those problems, one non-issue must be set aside. Defendant has not proffered an opinion (by its own industrial hygiene expert or otherwise) on the concentration of xylene or any other organic solvent within the containment. Plaintiffs suggest that in absence of a rival opinion on the question, defendant's challenge to the reliability of Caravanos's opinion is improper. (See Pls.' Letter Brief of 12/15/99, at 2, 3.) The Second Circuit, however, has recently clarified that a party challenging the admissibility of its opponent's expert witness is not required to first use its own expert to call the challenged expert's testimony sufficiently *172 into question before a district court may analyze the admissibility of the challenged expert's testimony. See Brooks v. Outboard Marine Corp., 234 F.3d 89, 91 (2d Cir.2000).
a. Defects Going to the Weight of Caravanos's Opinion on Xylene Concentration
Each of the figures Caravanos entered into his calculations could be challenged as to their accuracy. First, Caravanos calculated the volume of the containment based on an estimate that the containment was 60 feet long, 55 feet wide and 10 feet high. (See Def.'s Letter Brief of 12/6/99, Ex. C (spreadsheet).) Caravanos did not derive these numbers from a measurement of the bridge itself. Instead, he examined an engineering diagram of the bridge included among the daily inspection reports prepared by KTA-Tator, Inc., an independent paint inspector contracted by Amtrak. (Caravanos Dep. at 111.) The diagram specifies the length of each span of the bridge as 120 feet and specifies that the distance from the bottom of the bridge's undercarriage to the street is approximately 22 feet. (See Def.'s Letter Brief of 12/6/99, Ex. J (KTA-Tator records).) No other dimensions are specified on the diagram, and the diagram does not indicate whether it was drawn to scale. (See id.)
Nonetheless, Caravanos assumed that it was drawn to scale, measured the distance marked as 22 feet on the diagram with a ruler, measured the height of the undercarriage as depicted on the diagram, then extrapolated from the two measurements of the diagram to arrive at an estimate of 10 feet for the height of the undercarriage, and hence the height of the surrounding containment. (Caravanos Dep. at 115.) The only evidence presented at trial as to the height of the containment was Ralph P. Romano's testimony that it was 15 to 18 feet. (Tr. 6/24/98, at 47.) Even if measurement of the bridge itself bears out the low end of Mr. Romano's testimony (i.e., 15 feet), then Caravanos's estimate of the containment's height would be too low by a factor of 10/15. Since, in Caravanos's formula (viz., concentration = mass of xylene / volume), concentration is inversely proportional to the volume of the containment, which, in turn, is directly proportional to its height, the resulting figure for concentration would be too high by a factor of 15/10, or 50%, based on that potential inaccuracy alone.
In addition, Caravanos estimated that the containment was 60 feet long (i.e., half the length of one span), based on a discussion with Mr. Amorgianos in which Mr. Amorgianos indicated the containment did not cover an entire span. (Caravanos Dep. at 114.) Mr. Amorgianos's testified at trial, however, that the containment was 75 to 100 feet long, (Tr. 6/17/98, at 41), and Mr. Romano testified that it was "about 100 feet long," (Tr. 6/24/98, at 47). Again, since, in Caravanos's formula, concentration is inversely proportional to volume and, hence, length, even if the low end of Mr. Amorgianos's testimony is accurate, then Caravanos's estimate of length was too short by a factor of 60/75, and the resulting concentration too high by a factor of 75/60, or 25%, based on that inaccuracy alone.
If one combines the possible errors as to height and length, Caravanos's figure for concentration could be too high by a factor of at least 15/10 × 75/60 = 1125/600, or 87.5%. Both of these figures could have been determined precisely simply by measuring the bridge; Caravanos apparently made no attempt to do so.
In his current calculation, as evidenced by a spreadsheet he prepared after trial and which was introduced at Dr. Rutchik's deposition, Caravanos assumes that 25 gallons *173 of paint was used each workday. (Def.'s Letter Brief of 12/6/99, Ex. C.) Caravanos derives this estimate from a half-hour interview with Mr. Amorgianos. (Caravanos Dep. at 59-61, 117-18.) Invoices for the paint used on the Project might provide a more accurate estimate of the amount of paint used on the Project. Caravanos testified that those invoices were made available to him, (id. at 51, 79), but he relied on Mr. Amorgianos's estimate instead. This factor, again, goes to weight, since any discrepancy between the amounts suggested by the invoices and the 25 gallon estimate could be brought out on cross-examination.
The amount of xylene contained in the paint applied by Mr. Amorgianos, as actually thinned on the Project, is also in question. Caravanos estimated that the paint, as thinned, consisted of 10% xylene. (See Def.'s Letter Brief of 12/6/99, Ex. C (first spreadsheet).) To arrive at this figure, Caravanos began by noting the xylene content of the various paint products used on the Project:
(1) the first, primer coat (Con-Lux Zinc Plate 49 Type 2 Organic Primer Component A) consisted of 5% xylene by weight, and its corresponding thinner (Con-Lux Zinc Plate 49 Type 2 Organic Primer Component B) consisted of 29% xylene by weight, (see id., Ex. M (Material Data Safety Sheets for the paints and thinners used on the Project));
(2) the white, intermediate coat was mixed from two components; one (Con-Lux Epolon Mastic 81 Aluminum Component A) consisted of 3% xylene; the other (Con-Lux Epolon Mastic 81 Reactor B) consisted of 5% xylene; the corresponding thinner (Con-Lux Epolon Reducer 145) consisted of 49% xylene (id.);
(3) the red, third coat and its corresponding thinners (Con-Lux Acrolon II), however, did not contain any xylene, (id.; Tr. 6/18/98, at 52, 78 (Caravanos) (acknowledging that the red, third coat and its thinner did not contain any xylene)); and
(4) the fourth, anti-graffiti coat (Con-Lux Poly-Lon) also contained no xylene, (Def.'s Letter Brief of 12/6/99, Ex. M; Tr. 6/18/98, at 52, 78).
Since each paint was mixed with its corresponding thinner, Caravanos assumed that, with respect to the first two, xylene-containing coats, the resulting mixtures consisted of a percentage of xylene that lay somewhere between the percentage in the paint and the percentage in the thinner. (Tr. 6/18/98, at 71, 73, 77, 78.) Caravanos's choice of a final estimate of 10% for the first and intermediate coats appears to have been arbitrary; as Caravanos testified: "I decided instead of doing every single percentages [sic], the models for every single percentages [sic], to choose 10% xylene as a final sprayable primer and intermediate...." (Id. at 73; see also id. at 71.) Nonetheless, any inaccuracy introduced into the calculation thereby could presumably be challenged and quantified through testimony by the paint steward(s), who actually mixed the paint and thinner on the Project.
Finally, Caravanos assumed, for the purpose of his calculations, that the containment was absolutely air-tight and that, as a result, no xylene vapor escaped from the containment during the course of the workday. In deposition, Caravanos admitted that there may have been some seepage through the seams in the containment and its entryway. (Caravanos Dep. at 133-34.) Caravanos, however, testified plausibly that, given the containment's lead abatement function, it can be reliably assumed that the error introduced by this assumption was negligible. (Id.; Tr. 6/18/98, at 11-12.)
*174 All of these possible inaccuracies bring out possible errors in Caravanos's concentration figure that are either approximately quantifiable or likely negligible. These possible errors are thus amenable to probing on cross-examination or through the presentation of contrary evidence and only go to the weight of his opinion.
b. Defects Going to the Admissibility of Caravanos's Opinion on Concentration
There is, however, another defect in Caravanos's concentration opinion whose magnitude could not readily be brought out on cross-examination and which goes directly to its reliability and, hence, its admissibility. An expert opinion is admissible only
if (1) the testimony is based upon sufficient facts or data, (2) the testimony is the product of reliable principles and methods, and (3) the witness has applied the principles and methods reliably to the facts of the case.
Fed.R.Evid. 702 (emphasis added); see also Kumho Tire, 526 U.S. at 152, 153-57, 119 S. Ct. at 1176, 1176-79 (explaining that the objective of the Daubert gatekeeping requirement "is to make certain that an expert ... employs in the courtroom the same level of intellectual rigor that characterizes the practice of an expert in the relevant field," and excluding expert who did not follow his own stated methodology in forming his opinion). One fundamental assumption underlying Caravanos's calculations runs afoul of both of the emphasized requirements, i.e., it does not follow from a reliable application of his stated principles and methods, and it also contradicts plaintiffs' own evidence.
The model underlying Caravanos's calculation assumes that every single molecule of xylene within the paint (as thinned) was released from the paint as it left the sprayer and that every molecule of xylene that had been contained in the paint was in the air as of the end of the workday. (See Def.'s Letter Brief of 12/6/99, Ex. C (spreadsheet).) While this assumption certainly simplifies Caravanos's calculation, Caravanos has produced no justification for the assumption, either theoretical or empirical.
Caravanos explained in deposition that paint consists of two components: a solid fraction, viz., the pigment, and a liquid fraction that carries the pigment and makes it spreadable or sprayable, viz., the solvent. (Caravanos Dep. at 25, 77-78.) The process of paint drying is the process by which the liquid (solvent) fraction evaporates, leaving a solid layer of pigment behind. (Tr. 6/18/98, at 25, 75.) Caravanos testified at trial that the rate at which a solvent evaporates from paint (and, hence, the resulting concentration of solvent vapor in an enclosed space) depends on the volatility/vapor pressure of the particular solvent in question, temperature, humidity and "radiant energy", and that "proper exposure assessment" would include these variables. (Id. at 40-41, 75-76.)
However, as reflected on the spreadsheets introduced during his deposition and Dr. Rutchik's deposition, Caravanos did not include any of these variables in his calculations. (Def.'s Letter Brief of 12/6/99, Ex. C (spreadsheet).) Instead, he included only variables for the amount of paint used, its xylene content, and the volume of the containment, (see id.); in preparing his opinion, he considered the other variables, such as humidity, as "qualitative" factors. (Tr. 6/18/98, at 76 ("It was a qualitative factor that it was a dry day, so anything that evaporates would *175 evaporate more on a dry day.").)[16] This qualitative consideration is apparently the only basis for his assumption that the solvent evaporated from the paint completely as soon as it left the sprayer.
In addition to not being based on what Caravanos testified would be a "proper" calculation, this assumption contradicts evidence offered by plaintiffs as to the condition of the paint after it was applied. Specifically, Kpitikos testified that throughout the Project, the paint was unusually runny, (Tr. 6/23/98, at 25), thus indicating that a substantial amount of solvent remained in the paint after it was applied, i.e., that not all of the solvent evaporated from the paint immediately upon leaving the sprayer as Caravanos's calculation assumes. (See also Caravanos Dep. at 86 (stating that Mr. Amorgianos had told him the paint was "running and just not drying enough"); Tr. 6/18/98, at 73-74 (Caravanos) (noting that KTA-Tator inspection logs frequently indicated that the paint was runny).) Precisely or even approximately what degree of error Caravanos's simplifying assumption introduced into his final estimate of concentration cannot be determined without performing the very calculation that Caravanos testified should be done but which he omitted.
Because in preparing his opinion on concentration Caravanos did not follow the methodology that he testified was appropriate in his deposition (and hence did not apply his own stated methodology reliably) and, instead, based his calculation on an assumption that contradicts plaintiffs' own evidence as to the condition of the paint after its application (and hence did not "base[] [his opinion] upon sufficient facts or data"), his testimony is excluded as unreliable. Fed.R.Evid. 702.
This latter defect in Caravanos's opinion on concentration appears to be one that he could remedy. Given his credentials in quantitative industrial hygiene, which have not been disputed, Caravanos could presumably perform the calculations necessary to estimate the evaporation rate of xylene and the other organic solvents from the paint used on the Project given the atmospheric conditions that existed on the relevant dates. Plaintiffs are, therefore, given leave to supplement Caravanos's expert report to include a calculation of concentration that includes a quantitative (rather than "qualitative") assessment of the temperature, pressure and humidity along the lines Caravanos testified would be included in a "proper exposure assessment," (Tr. 6/18/98, at 40-41, 75-76), but which Caravanos did not in fact perform.
Notably, plaintiffs argue that any error introduced into Caravanos's calculations are irrelevant because Caravanos testified at trial that even if his calculations were off by 90% or even 95%, his previously stated opinion that the concentration of xylene in the containment was "sky high" and "many, many levels above standard, acceptable levels," (id. at 40), would not change. (Id. at 109-10.) Plaintiffs' reliance on this testimony is misplaced: if Caravanos's calculation of 500 ppm to 2000 ppm of xylene were off by 95%, that would mean that the actual levels of xylene were 25 ppm to 100 ppm. Such an error would make a difference, for the OSHA PEL for *176 xylene is 100 ppm and Caravanos opined at trial that a person "could work at 100 part[s] per million all day long most of the time and not suffer any health effects." (Id. at 40-41.)
B. Duration
On the issue of duration of exposure, plaintiffs have proffered Caravanos and Dr. Rutchik as experts. However, contrary to the apparent assumption of both plaintiffs and defendant, the issue of duration is not one for which the opinion of "a witness qualified as an expert by knowledge, skill, training, or education" "will assist the trier of fact to understand the evidence or to determine a fact in issue." Fed.R.Evid. 702.
The duration of Mr. Amorgianos's exposure to xylene-containing paint products turns on three questions: (1) How many days was Mr. Amorgianos involved in painting inside the containment?, (2) Which paint products were used on each of those days?, and (3) How long was Mr. Amorgianos inside the containment on the days, if any, that he used the xylene-containing paints (viz., Epolon Mastic and Zinc Plate 49)? These are questions of fact about what actually transpired on the Project between July 22, 1995 and August 28, 1995; their determination does not require or benefit from Caravanos's expertise in industrial hygiene or Dr. Rutchik's expertise in neurology and toxicology. Moreover, neither Caravanos nor Dr. Rutchik has any direct, personal knowledge of Mr. Amorgianos's work activities on the Project, but instead have formed opinion about the duration of his exposure based on interviews with Mr. Amorgianos and reviews of time records and daily inspection reports for the Project.
To the extent these records require interpretation, none of the experts proffered by either party possesses the relevant expertise. For example, on the Romano time sheets, the notations "B," "P" and "S" appear beside the entries for the number of hours each crewman worked. Certain questions posed to Dr. Rutchik during his deposition suggest that these notations stand for "Blasting," "Painting" and "Spraying," and are intended to indicate what activity each particular crewman was performing on a given workday. The only witnesses qualified to explain the import, if any, of these notations are the individual(s) who prepared the records or any other Romano employee familiar with this notation system, provided some proof is made that it reflects a standard notation system used by the company. Accordingly, to the extent that plaintiffs are proffering Caravanos or Dr. Rutchik to testify on the duration of Mr. Amorgianos's exposure to xylene-containing paints, their opinions are excluded as falling outside the area of their expertise and otherwise outside their personal knowledge.
Although defendant correctly observes that an expert opinion on general causation must "fit" the facts of the case, including underlying facts regarding exposure, this last ruling does not mean that Caravanos or Dr. Rutchik (or Dr. Moline) cannot for this reason testify on the issue of general causation. In order for their opinions on general causation to "fit" the facts of the case, their opinions need only be "based upon sufficient facts or data." Fed.R.Evid. 702. Since the question of which paints Mr. Amorgianos was exposed to, on which days and for how long, are essentially ones of historical fact, an otherwise reliable general causation opinion will be admissible as long as it is predicated on assumptions regarding duration of exposure that a reasonable juror could find correct based on admissible evidence, such as Mr. Amorgianos's testimony or the time records and daily inspection reports.
*177 As stated in their letter brief, plaintiffs now intend to offer general causation opinions that are predicated on an assumption that Mr. Amorgianos was spray-painting xylene-containing paints "on the three days prior to and including August 28, as well as intermittently during the 30 day period prior thereto." (Pls.' Letter Brief of 12/15/99, at 4.) Although Amtrak contests that Mr. Amorgianos himself was spray-painting on every day that any painting was done on the Project, Mr. Amorgianos's testimony, the time records and the daily inspection reports together provide sufficient evidence on which a reasonable juror could find that plaintiffs' claim as to the duration of Mr. Amorgianos's exposure to xylene-containing paint is correct. See infra Appendix tbl. 4 (summarizing the time records and daily inspection reports).
In addition, plaintiffs' current position on the number of hours Mr. Amorgianos spent painting on any given day that he painted at all also has sufficient support in the record. After noting in his report that Caravanos's concentration calculations were based on an eight-hour workday, Dr. Rutchik states: "[I]t is likely that Mr. Amorgianos was painting for closer to three to five hours per day and in the early part of the day. He may not have been in the enclosed space painting either before or after." (Def.'s Letter Brief of 12/6/99, Ex. D, at 12.) These assumptions are consistent with the KTA-Tator daily inspection reports, which, in some instances, record the start and stop times for the spray-painting on a given day, (see, e.g., id. Ex. J (KTA-Tator Daily Painting Inspection Report for 7/29/95, at 2) (noting that spray-painting began at 11:00 a.m. and ended at 2:00 p.m.)), and with trial testimony of various witnesses that a certain amount of time each work day was spent preparing to paint and on other non-painting activities.
Accordingly, to the extent plaintiffs' experts' opinions on general causation are based on an exposure duration of approximately 3 to 5 hours per day, on August 28, 1995, the three preceding days, and intermittent days in the preceding 30-day period,[17]and to the extent they are otherwise competent and reliable, those opinions are "based upon sufficient facts or data." Fed. R.Evid. 702.
(3)
Plaintiffs have proffered each of Dr. Moline, Dr. Rutchik and Caravanos on the issue of general causation, i.e., on the issue of whether exposure to xylene in the amount and for the duration allegedly experienced by plaintiff can cause the complex of CNS and PNS symptoms from which he allegedly suffers. Each of these experts bases his or her opinion principally on existing medical literature. As discussed above, Discussion (1) (B), Defendant's motion requires the court to determine whether these experts' conclusions regarding general causation were extrapolated from the medical literature in a scientifically reliable fashion. To do so, it is necessary first to specify more precisely the exact hypothesis that plaintiffs' experts are offering.
The issue in this case is not whether exposure to some organic solvent in some dose and for some duration can cause *178 some effect of some duration on the CNS and/or PNS. The issue is whether exposure to xylene in the amount and for the duration alleged by plaintiffs can cause CNS and PNS symptoms of the type, magnitude, and duration allegedly suffered by Mr. Amorgianos. The medical evidence on which plaintiffs' experts rely, of course, need not precisely match the specifics of this case in those respects, but it must at least be in the same ballpark.
In view of the fact that Mr. Amorgianos worked as a painter for twenty years, (see Tr. 6/17/98, at 37-38), it must be noted at the outset that plaintiffs are not claiming that Mr. Amorgianos had a pre-existing condition which was exacerbated or brought to a clinical level by his exposure during the Steinway Street Bridge Project. Plaintiffs themselves and their experts made clear in their trial and deposition testimony that they are attributing Mr. Amorgianos's alleged neurological conditions solely to his exposure during the Project: Mr. Amorgianos testified to a dramatic change in his health condition after August 28, 1995, (see id. at 95-96); Mrs. Amorgianos testified that before August, 1995, her husband had "never" become ill at work before, (id. at 129); and Dr. Moline testified based on Mr. Amorgianos's medical records that he "went to work fine in August," worked in an enclosed space with high levels of chemicals, and showed symptoms immediately thereafter, (see id. 6/18/98 at 132). Finally, plaintiffs' new expert on toxicology and neurology, Dr. Rutchik, put plaintiffs' causation claim in its starkest form:
Q Is it your opinion that Mr. Amorgianos's present health is a result of his exposure to organic solvents for a period of time prior to his exposure at the [Steinway Street Bridge] project?
A No.
Q So is it your opinion that his exposure in this case is exclusively related to his exposure at the [Steinway Street Bridge] project?
A. Yes.
(Rutchik Dep. at 203 (emphasis added).)
Accordingly, the hypothesis at issue here is that exposure to xylene in amounts averaging 500 to 2000 ppm on August 28, 1995 and each of preceding three workdays, and for three to five hour periods on intermittent days in the preceding thirty days can, as a general matter, cause the complex of CNS and PNS symptoms that Mr. Amorgianos alleges.
To inform the analysis of whether plaintiffs' experts have reliably extrapolated their opinions on this general causation issue from the medical literature they cite, it will be helpful first to review the relevant chemical and medical terminology used in the literature. The discussion will then turn to an analysis of each expert's opinion.
A. Chemical Terminology
The term "organic solvent" identifies a general class of hundreds of chemical compounds that differ widely in structure and composition. Organic solvents as a class share only two characteristics: they are volatile (i.e., tend to evaporate rapidly on exposure to air) at room temperature and lipophilic.[18]See Roberta F. White & Susan P. Proctor, Solvents and Neurotoxicity, 349 Lancet 1239, 1239 (1997) (cited by *179 Dr. Moline). The most common organic solvents are aromatic hydrocarbons, such as benzene, toluene, and xylene, which are based on rings of six carbon atoms; aliphatic hydrocarbons, such as hexane, which are based on strings of carbon atoms of varying lengths; aldehydes, such as acetalaldehyde, which are based on a carbonyl (CO) group that is bonded to a hydrogen atom and another hydrocarbon; alcohols, such as methanol and ethanol, which are based on hydrocarbon chains that include a hydroxyl (OH) group; esters, such as ethyl acetate; ethers, which consist of an oxygen atom bonded to two hydrocarbon chains; nitrohydrocarbons, such as ethyl nitrate; ketones, such as acetone and methylethylketone, which are based on a carbonyl (CO) group that is bonded to two other hydrocarbons; halogenated hydrocarbons, such as carbon tetrachloride and trichloroethylene (TCE); cyclic hydrocarbons, such as cyclohexane; and glycols, such as ethylene glycol, which are hydrocarbons containing two hydroxyl (OH) groups. See id. at 1239. The term "organic solvents" thus comprises a wide and varied class of compounds with few structural similarities to one another. See id.
The use of organic solvents is ubiquitous in industry. Organic solvents are used for a multitude of purposes, including degreasing machine parts, automobile manufacturing and repair, electronics manufacturing, dry cleaning, and the manufacture of paints, varnishes, and thinners. See id. Individual organic solvents and mixtures of various organic solvents are components of many products, including paints, varnishes, adhesives, glues, coatings, degreasing and cleaning agents, dyes and inks, floor and shoe polishes, waxes, agricultural products, and fuels. See id.
The particular organic solvent identified by plaintiffs' experts as the "primary culprit" in this case is xylene. Xylene, C6H4(CH3)2, consists of a benzene ring in which two of the hydrogen atoms attached to the central six-carbon ring have been replaced by methyl (CH3) groups.[19] Xylene comes in three isomers, or structural forms meta-xylene (m-xylene), ortho-xylene (o xylene), and para-xylene (p-xylene), which differ from one another structurally, in terms of the relative position of the two methyl groups on the carbon ring, and chemically, in terms of physical properties, such as boiling point or freezing point. See Agency for Toxic Substances & Disease Registry, U.S. Dep't of Health & Human Servs., Toxicological Profile for Xylenes (Update) (1995). Most commercial preparations of xylene consist of a mixture of the three isomers. See id. Xylene in each of its three isomers is a colorless, flammable liquid with a sweet odor. See id.
Commercial xylene is derived from petroleum, and is one of the top thirty chemicals produced in the United States in terms of volume. See id. Xylene is used for a number of industrial purposes, including the manufacture of plastics, synthetic fabrics, and paper, as well as in the printing, rubber, and leather industries. See id. Xylene is also an ingredient in a number of commercial products, including industrial cleaning agents, airplane fuel, gasoline, and most pertinent to this action paints and paint thinners. See id. As noted previously, the primer and intermediate coats used on the Steinway Street Bridge Project and their corresponding thinners contained xylene in varying amounts, while the third, pigmented coat and the anti-graffiti coat, and their corresponding thinners did not contain any xylene. See supra Discussion (2) (A) (2) (a).
*180 B. Medical Terminology
1. The Nervous System
The human nervous system has two components: the central nervous system (CNS) and the peripheral nervous system (PNS). See Principles of Neural Science 273 (Eric R. Kandel et al. eds., 3d ed.1991). The CNS, which consists of the brain and the spinal cord, is the locus of cognition, behavior, memory, and emotion, as well as the control of voluntary and reflex movements. See id. at 273, 275-78. The PNS consists of neurons and ganglia that lie outside the brain and spinal cord, and is responsible for carrying sensory information from the body to the CNS and for regulating the function of various internal organs and other internal bodily processes. See id. at 273-74.
2. WHO Classification Scheme for Toxically Induced CNS Disorders
As evidenced by the literature cited by plaintiffs' experts, the effect of organic solvents on the CNS (and PNS) function was, at least during the 1970s and 1980s, an area of interest to the medical community. In order to facilitate communication between, and to achieve some uniformity of diagnosis among, researchers and clinicians, a 1985 World Health Organization ("WHO") working group established a standard classification scheme for CNS symptoms suspected to be associated with workplace chemicals, including organic solvents, metals, and pesticides. See Edward L. Baker, Organic Solvent Neurotoxicity, 9 Ann. Rev. Public Health 223, 227 (1988) (cited by Dr. Moline); Edward L. Baker & Lawrence J. Fine, Editorial, Solvent Neurotoxicity, 28 J. Occupat'l Med. 126, 127 (1986) (cited by Dr. Moline).
The WHO classification scheme consists of five syndromes, or clusters of symptoms, some of which are acute and some of which are chronic in nature. Because the hypotheses discussed in the medical literature are often framed in terms of one or more of these five syndromes, it will be helpful to outline the WHO scheme. It must be borne in mind, however, that the WHO scheme is only a set of diagnostic categories, not a hypothesis that any particular chemical causes any of the diagnostic syndromes so described.
Acute intoxication can last for minutes to hours, with no residual effect. Symptoms include acute depression of CNS function and psychomotor impairment.
Acute toxic encephalopathy is clinically characterized by confusion, coma, and/or seizures. On a physiological basis, acute toxic encephalopathy may be caused by cerebral edema (i.e., "[a]n accumulation of an excessive amount of watery fluid in cells, tissues, or serous cavities,") Stedman's Medical Dictionary 489 (25th ed.1990), damage to the capillaries in the CNS, and hypoxia (i.e., oxygen starvation, see id. at 756), and its residual effects may include permanent cognitive deficits.
There are three chronic syndromes in the WHO classification scheme. Organic affective syndrome is characterized by mood disturbances, such as depression, irritability, fatigue and anxiety. It may last for days to weeks, but has no residual effects.
Mild chronic encephalopathy is characterized by fatigue, mood disturbance, and cognitive complaints. It has an insidious onset and may endure for weeks. Cognitive deficits may include attentional impairment, motor slowing or incoordination, visuospatial effects, and short term memory loss. Improvement may occur in absence of exposure, but in some cases permanent mild cognitive deficits may also occur.
Finally, severe chronic toxic encephalopathy is characterized by cognitive and *181 affective changes sufficient to interfere with daily living. Typical cognitive deficits are of the same types seen in cases of mild chronic toxic encephalopathy, but are more severe. Neurological abnormalities may be observed on some neurophysiological or neuroradiological measures, such as CT and MRI scans, electromyography, and electroencephalography. Severe chronic toxic encephalopathy has an insidious onset and results in irreversible, permanent cognitive dysfunction. See White & Proctor, supra, at 1241; Baker & Fine, supra, at 127 & tbls. 1-2.
3. Peripheral (Poly-)Neuropathy
Although the WHO workgroup focused on categorizing the potential cognitive and behavioral CNS effects of organic solvents and other workplace chemicals, a significant amount of research has also been directed toward the possible effects of organic solvents on the PNS and on the motor axons of the CNS, which originate in the spinal cord but run in the peripheral nerves, see Principals of Neuroscience, supra, at 250, 274. Of greatest importance to the present case is the question of whether organic solvents (including xylene) can cause peripheral neuropathy or peripheral polyneuropathy ("PN"). "Neuropathy" is a general term that denotes "any disorder affecting any segment of the nervous system," Stedman's Medical Dictionary 1048 (25th ed.1990), while "peripheral neuropathy" or "peripheral polyneuropathy" is a somewhat more specific term that denotes a "disease process involving a number of peripheral nerves," id. at 1236. PN usually affects both sensory and motor function. See Principles of Neuroscience, supra, at 250. Sensory disorders associated with PN include numbness, tingling, and phantom pains; in addition, sensitivity to touch, temperature, and vibration, may be decreased. See id. Typically, these effects are most pronounced at the extremities and manifest themselves in a characteristic, symmetrical "glove-and-stocking" pattern. See id.; Baker & Fine, supra, at 126. Motor disorders associated with PN are manifested by weakness and by decreased or absent reflexes. See Principles of Neuroscience, supra, at 250. PN can be caused by a wide variety of conditions, including genetic diseases, such as porphyria; Guillain-Barre syndrome; diabetes; vitamin B12 or thiamine deficiencies; lead poisoning; alcoholism; carcinomas; and certain immunological disorders. See id. In addition, as will be discussed at greater length below and in the Appendix, three workplace chemicals methyl n-butyl ketone (Mn BK), n-hexane, and carbon disulfide (which is not an organic solvent) are generally accepted in the medical community as causes of PN. See Casarett & Doull's Toxicology, supra, at 471-74.
C. Xylene's Acute Intoxicating and Eye Irritating Effects
Before proceeding with analyses of Dr. Moline, Dr. Rutchik, and Caravanos's opinions on general causation, one last non-issue must be addressed. To the extent plaintiffs' experts' opinions on general causation relate to the cause of the acute intoxication or eye irritation allegedly suffered by Mr. Amorgianos in the two- to three-day period following his departure from the Steinway Street Bridge Project, they are admissible. The articles relied upon by plaintiffs' experts, as well as the toxicology and industrial hygiene texts they cited as authoritative in their depositions, make abundantly clear that it is generally accepted in the medical community that exposure to xylene in the amount now alleged by plaintiffs 500 to 2000 ppm even for periods of a few hours can cause eye irritation and the symptoms of acute toxic intoxication described by Mr. Amorgianos, viz., dizziness, nausea, loss of coordination, disorientation, and headaches, *182 among others.[20] Moreover, xylene's acute narcotic effects and status as an eye irritant are two of the three adverse health effects relied upon by OSHA in formulating its PEL and STEL for xylenes (the other being adverse serological effects). See Air Contaminants, 54 Fed.Reg. 2332, 2477 (1989) (final rule amending 29 C.F.R. § 1910.1000). Thus, although neither party has focused on the issue of what caused the alleged acute health problems suffered by Mr. Amorgianos at the end of workday on August 28, 1995 and the subsequent few days,[21] there is clearly a reliable basis in the cited medical literature for plaintiffs' experts' opinions on general causation insofar as they relate to the symptoms of eye irritation and acute intoxication during the two- to three-day period following Mr. Amorgianos's departure from the Steinway Street Bridge Project. See Daubert, 509 U.S. at 594, 113 S. Ct. at 2797 (stating that "[w]idespread acceptance can be an important factor in ruling particular evidence admissible"). Accordingly, defendant's motion to exclude is denied with respect to that aspect of plaintiffs' experts' opinions on general causation.[22]
D. Dr. Moline
Bearing in mind the factors discussed in Daubert and Joiner, as well as the relevant epidemiological principles sketched above, I have attempted to assess the support that the articles cited by Dr. Moline lend to her opinion, on both an individual and a cumulative basis. Only a brief review of the cited literature and a cumulative assessment appears here; an extended analysis of each individual article or work appears in a separate appendix following this opinion, see infra Appendix tbl. 1.
Upon review, the medical literature cited by Dr. Moline does not provide a reliable basis for her opinion on causation. Dr. Moline was asked in deposition to identify the articles on which she relied in forming her opinion. In an erratum letter to her deposition, she cited nine articles. (See Letter from Dr. Moline to Plaintiffs' Counsel of 3/10/98.) Three are cross-sectional studies (i.e., studies in which a group of randomly selected, exposed subjects is tested for various symptoms, with or without a reference group of unexposed subjects), two are uncontrolled case-series reports that examined exposed subjects who already presented the symptoms in question, and four are review articles, which summarize the results of existing studies. See infra Appendix tbl. 1.
*183 The three cross-sectional studies-Fidler et al. (1987), Gregersen et al. (1984), and Seppalainen (1978)-each present serious problems of "fit" with the present case, in terms of the type of chemicals the subjects were exposed to, the duration of their exposure, and the resulting symptoms (or lack thereof). Fidler et al. (1987) studied 101 currently exposed workers, whose exposure was described simply as being to "paint," for an average of 18 years, as opposed to Mr. Amorgianos's intermittent exposure over a 38-day period. See id. While these authors found that the subjects reported a range of acute, subjective CNS symptoms (e.g., dizziness, nausea, fatigue, etc.), the authors conceded they were unable to associate the level of exposure with objective neurobehavioral deficits, and they did not study possible PNS effects at all. See id. Gregersen et al. (1984) studied 65 workers, only 10 of whom were painters, most of whom had never worn respirators, and who had been exposed to various organic solvents, primarily white spirit, perchloroethylene, toluene and styrene (rather than xylene), for an average of 12.9 years. See id. Although the authors again found a higher incidence of acute CNS effects in the exposed group, they found no statistically significant association between solvent exposure and peripheral neuropathy and declined to reach a conclusion as to whether the observed CNS effects were transient or permanent in nature, on the latter point citing the inherent limitations of a cross-sectional study design. See id. Finally, Seppalainen (1978) administered EEGs and EMGs to a group of 102 car painters who had been exposed primarily to a mixture of toluene, xylene, butyl actate and white spirit. See id. Although Seppalainen found support for an association between mixed solvent exposure and "slight" PNS effects, the subjects in her study were exposed for an average of 14.8 years. See id. Moreover, she found no significant difference in the EEG results (CNS effects) for the painters as compared to the unexposed reference group. See id.
The two uncontrolled case-series reports, in addition to being epidemiologically weak evidence of a causal relationship, see Rom, supra, at 44-45, also fail to fit the facts of the case as alleged by plaintiffs. Morrow et al. (1989) administered the Minnesota Multiphasic Personality Inventory to 22 occupational medicine patients with an average of 7.3 years of exposure to unspecified organic solvents. See id. Linz et al. (1986) performed physical exams, blood tests, and neuropsychological evaluations on fifteen industrial painters, who were already seeking treatment for various neurological problems. See id. These patients had been exposed (without adequate protection or ventilation) to unspecified organic solvents for periods of 3-4 months to 24 years (as opposed to Mr. Amorgianos's intermittent exposure of a 38-day period). See id. The authors found a higher incidence of abnormal PNS and CNS symptoms in the 15 painter/patients as compared to general norms, but authors noted that they merely assumed that the patients results were normal before exposure and expressly "presum[ed]" that there was a causal relationship between their exposure and their neurological results. See id.
None of the four review articles discusses xylene specifically, and none provides any conclusion as to the dose or duration of exposure to any particular organic solvent required to produce chronic CNS or PNS effects. See id. Moreover, the underlying studies cited by the authors of these review articles reveal exposure histories very different from Mr. Amorgianos's. White & Proctor (1997) discussed the case of an individual with 32 years of exposure, including 30 years of *184 unprotected exposure to xylene, and benzene, toluene and methylethylketone (none of which were present in the paint products used on the Project). See id. Baker (1998) discusses studies involving individuals who were exposed to a variety of unspecified solvents for 9-10 years. See id. Baker et al. (1985) report PNS effects only with respect to n-hexane and Mn BK, and, with regard to CNS effects, states only that symptoms consistent with toxic encephalopathy may appear after "heavy expos[ure] ... over a period of months to years." See id. The authors do not report any conclusion as to the effect of exposures for a period of days to weeks, as alleged by Mr. Amorgianos. See id. Finally, Baker & Fine (1986) concluded that the acute intoxicating effects of organic solvents, generally, are well-established; that acute toxic encephalopathy, while a recognized effect of exposure to lead and mercury, "has not been described as a characteristic finding in excessive short-term solvent exposure;" that organic affective syndrome occurs in individuals with chronic solvent exposure (dose, duration, or particular solvent unspecified); and that the only convincing evidence of chronic toxic encephalopathy has come from studies of individuals who have deliberately abused solvent-containing products such as model glue.[23]See id. Baker & Fine (1986) further noted that no pathogenic explanation of the effect of solvent exposure on the CNS has been given and no dose-response relationship has been found. See id. With regard to PNS effects, they concluded that convincing evidence of "distal, symmetrical sensorimotor peripheral neuropathy has been clearly demonstrated following exposure of humans and animals to several specific solvents: n-hexane, methyl-n-butyl-ketone (MBK) and carbon disulfide" (emphasis added), but cautioned that the relationship between other solvents and specific agents has not been elucidated and noted that the rates of PNS toxicity in solvent-exposed groups have generally been lower than the rates of CNS toxicity. See id.[24]
*185 In sum, none of the articles cited by Dr. Moline attributes clinical PNS effects to solvents other than n-hexane, Mn BK, or carbon disulfide, and those that do find evidence only of a symmetrical peripheral neuropathy. None of the articles provides evidence on the CNS effects of short-term exposure to xylene or any other organic solvent, as opposed to long-term exposures of several months to many years. All involve individuals exposed to a variety of organic solvents (a) other than or in addition to xylene, (b) many of which were not present at all in the paint products Mr. Amorgianos used, (c) for a much longer period of time than Mr. Amorgianos. Only three of the studies evaluated a random cross-section of exposed subjects, the largest of which evaluated a group numbering only 102 subjects. Cf. Washburn, 2000 WL 528649, at *2, 213 F.3d 627 (holding that expert opinion was properly excluded where, inter alia, it relied on anecdotal reports and small-scale epidemiological studies with few controls). And none involved a follow-up study of even a majority of the subjects to determine whether the reported symptoms were permanent or transient.
Under these circumstances, there is too great an "analytical gap" between the conclusions reached by the authors of Dr. Moline's cited articles and the conclusions that she draws from their work, viz., that intermittent exposure to xylene at 500 to 2000 ppm for 3-5 hours per day, on intermittent days throughout a 38-day period can cause an a symmetrical peripheral neuropathy of permanently disabling severity, as well as cognitive and neurobehavioral deficits of disabling severity, which persist unchanged for a period of three years after cessation of exposure. The type and magnitude of the effect and the type and magnitude of exposure between which Dr. Moline posits a causal relationship are simply not in the same ballpark as the exposures and effects discussed in the cited literature and, therefore, cannot be reliably extrapolated from that literature. Further, in light of the studies and case histories cited by Dr. Moline, a case in which subacute workplace exposure to xylene caused the type of permanent, CNS and asymmetrical PNS conditions claimed by Mr. Amorgianos, would appear to be unusual and presumably would make for a publishable case history. Therefore, the fact that Dr. Moline, a specialist in occupational medicine, has chosen not to subject her assessment of Mr. Amorgianos's case to the scrutiny of her peers is particularly telling and constitutes an additional factor weighing in favor of exclusion. See Daubert, 509 U.S. at 593, at 113 S. Ct. at 2797. For all these reasons, defendant's motion to exclude Dr. Moline's opinion on general causation with respect to Mr. Amorgianos's alleged chronic PNS and CNS conditions is granted.
E. Dr. Rutchik
Dr. Rutchik is a board-certified neurologist and has completed a clinical fellowship in neurotoxicology. (Rutchik Dep. at 307, 396.) Dr. Rutchik based his opinion on general causation on nineteen articles, including nine cross-sectional studies (three of which studied data from the same test group), two follow-up studies, two uncontrolled case-series studies, four case reports, one animal study, and one review article on the anatomy and pathology of the peripheral nerve. See infra Appendix tbl. 2.
The nine cross-sectional studies cited by Dr. Rutchik were all small in scale; the largest subject group studied consisted of 187 workers (Bleecker et al. (1991)). Moreover, the authors of the latter study found no signs of peripheral neuropathy and rejected the hypothesis that there was an association between chronic, low dose *186 solvent exposure and organic affective syndrome. As with the studies cited by Dr. Moline, each of these nine studies presents problems of "fit," both with respect to the type of exposure and effects reported. Most of these studies involved subjects who either were exposed to xylene in combination with other solvents not used on the Project or not exposed to xylene at all. Similarly, where specified, the studies involved subjects with mean durations of exposure of between 14.8 to 30 years. With regard to the effects of such long-term exposure, four reported subclinical CNS effects indicative of acute intoxication or organic affective syndrome, seven found subclinical PNS effects, and two found no evidence of any PNS effect at all. None reported evidence of chronic CNS conditions or peripheral neuropathy of clinical severity. None reported any asymmetrical PNS effects. And only one found a dose-response relationship between exposure and the observed symptoms; significantly, that dose-response relationship only emerged when workers with fewer than ten years of exposure were excluded, and the effect in question was "painter's syndrome" (i.e., organic affective disorder or neurasthenia), not peripheral neuropathy or chronic toxic encephalopathy (mild or severe). See infra Appendix tbl. 2.
The two follow-up studies, Antii Poika (1982) and Seppalainen & Antii Poika (1983), examined data from follow-up examinations of 87 of 106 patients diagnosed three to nine years earlier with chronic solvent intoxication after occupational exposure. As discussed in the later article, only 61% of these patients were exposed to xylene, and those that were were also exposed to a number of other solvents in larger quantities. The authors disclaimed the ability to relate the observed PNS and CNS conditions to particular solvents. Moreover, the observed PNS and CNS effects were "slight" in degree, often with improvement "to a normal or almost normal state" over time. Finally, the authors found no dose-response relationship between solvent exposure and any PNS or CNS condition.
The two uncontrolled case-series reports, Seppalainen et al. (1980) and Linz et al. (1986), also do not "fit" the facts of this case, as alleged by plaintiffs. Seppalainen et al. (1980) studied 107 patients previously diagnosed as having suffered solvent poisoning after long-term exposure. The male subjects were exposed for an average of 9.6 years, and over half of the subjects were primarily exposed to the non-paintrelated solvents trichloroethylene (a degreasing agent) and perchloroethylene (an ingredient in dry cleaning fluid). The authors found slightly abnormal EEGs (a CNS effect) and slowed nerve conduction velocities (a PNS effect), but no cases of actual paresis and no dose-response relationships.[25]
Given their anecdotal nature, the four case reports would for that reason alone probably not provide an epidemiologically reliable basis for an opinion on causation. See Rom, supra, at 44-45 (discussing the epidemiological significance of uncontrolled case studies and case-series reports). However, even leaving that general objection aside, none of them provides reliable support for Dr. Rutchik's opinion, and, indeed, they tend to illuminate the analytical gap between Dr. Rutchik's causal opinion and the types of exposures and effects reported in the literature. Morley et al. (1970) is one of the most-often cited articles concerning the acute intoxicating effects *187 of organic solvents. In that case, three male workers began painting without respirators inside a tank in a ship's engine room at 10:30 a.m. The tank measured seventeen feet wide by seventeen feet long by four feet eight inches high and had virtually no ventilation. The workers lost consciousness while inside the tank and were not discovered until 5 a.m. the next day. The air inside the tank was estimated to contain 10,000 ppm xylene (i.e., five times Caravanos's current estimate of the upper bound on Mr. Amorgianos's exposure). One man died, showing signs on autopsy of liver damage and acute pulmonary edema; the other two men completely recovered with no residual effects two to three days later. Thus, despite 18.5 hours of continuous exposure to a much higher concentration of xylene than Mr. Amorgianos claims, no permanent effects were observed in the surviving Morley subjects.
Hipolito (1980), which was authored by a laboratory technician rather than a doctor or scientist, reports five cases of xylene poisoning in laboratory workers. The most severe case was that of a fifty-eight year-old woman who had worked with xylene for fifteen years in an unventilated, six by eight foot room. After eleven years she began to complain of, inter alia, headaches, nausea, dyspnea and flushes. After fifteen years, she collapsed with severe chest pain, did not work thereafter, and was only capable of limited self-care. Notably, the onset of these symptoms came after a much longer period of exposure than Mr. Amorgianos's (eleven years as opposed to thirty-eight days), and even then, the onset was insidious, as opposed to Mr. Amorgianos's claim of a sudden onset of permanently disabling CNS and PNS effects.
Means et al. (1976) reports the case of seven men aged seventeen to twenty-two years, who habitually and intentionally inhaled vapors from the same brand of lacquer thinner in order to "get high." These young men's solvent abuse resulted in a symmetrical peripheral neuropathy. Interestingly, despite the fact that the lacquer consisted of 43.6% xylene by volume, the authors attributed the PNS effects to a different ingredient, 2 heptanone, in view of its structural similarity to Mn BK, one of the three chemicals known to cause PN. Given that Means et al. declined to attribute the PNS effects they observed to xylene simply because it was the most prevalent solvent in the lacquer, it is highly questionable how Dr. Rutchik can reliably conclude from their work that xylene can cause PN. Cf. Joiner, 522 U.S. at 145, 118 S. Ct. at 518 ("Given that Bertrazzi et al. were unwilling to say that PCB exposure had caused cancer among the workers they examined, their study did not support the experts' conclusion that Joiner's exposure to PCBs caused his cancer.")
Finally, Klaucke et al. (1982) reports that fifteen employees at a hospital experienced headache, nausea, vomiting, dizziness, and eye, nose and throat irritation after xylene leaked into the hospital's ventilation system, resulting in an ambient xylene concentration estimated at 700 ppm. The authors reported that all of the patients' symptoms resolved within 48 hours, with no permanent effects noted.
The animal study cited by Dr. Rutchik, Padilla & Lyerly (1989), studied the effects on the axonal transport in rats that were exposed to varying concentrations of xylene for varying periods of time, from 50 ppm for a single 6 hour exposure, to 1600 ppm, 5 days per week, for 6 hours per day, for 1.5 weeks. A significant reduction in axonal transport was observed only at exposures of 800 ppm or 1600 ppm for 1.5 weeks. The rats were retested after thirteen days, with the 1600 ppm rats continuing to show decreased axonal transport. *188 The "analytic gap" between a reported effect on rat neurons, which lasted for thirteen days, and the conclusion that xylene can cause neuronal damage in humans that persists for three years or more is simply too great for the resulting opinion to be reliable.
Finally, the review article on the anatomy and pathology of peripheral nerves, Schaumburg & Spencer (1976), is expressly limited to three solvents other than xylene, viz., n-hexane, Mn BK and 2,5 hexanedione.
In sum, as is the case with the medical literature cited by Dr. Moline, Dr. Rutchik's cited articles fail to "fit" the facts of this case, either in terms of the type and duration of exposure, or the type and duration of the observed effects. The articles cited by Dr. Rutchik involved subjects with years of exposure to a variety of solvents other than, or in combination with, xylene, and the observed symptoms were either those of acute intoxication; or subclinical or subjectively symptomatic PNS and CNS effects, with little evidence that such effects are permanent. Few, if any, dose-response relationships were reported, and none of the studies or case reports report cases of asymmetrical peripheral neuropathy. See also Hazardous Materials Toxicology, supra, at 149 (cited by Dr. Rutchik as authoritative) ("Toxic neuropathies commonly present with clinical patterns of symmetrical polyneuropathy...."). Moreover, Dr. Rutchik prepared his opinion for litigation, rather than as part of his academic research, and he has not seen fit to share his opinion that intermittent exposure to xylene over a 38 day period can cause CNS and asymmetrical PNS deficits of permanently disabling severity. For all these reasons, defendant's motion to exclude Dr. Rutchik's general causation opinion with respect to Mr. Amorgianos's alleged chronic conditions is granted.
F. Caravanos
1. Xylene
In deposition, Caravanos acknowledged his estimates of xylene concentration might not be accurate, but explained that even if the actual levels were substantially lower, his opinion on causation would remain the same. When asked what is the minimum level of exposure necessary to cause the chronic effects alleged by Mr. Amorgianos, Caravanos responded that "one day exposure to 500 parts per million of xylene is possible to see the effects that Mr. Amorgianos has." (Caravanos Dep. at 162.) When asked on what basis he had reached that conclusion, Caravanos cited six article abstracts and the documentation accompanying the American Conference of Governmental Industrial Hygienists' ("ACGIH") published threshold limit value ("TLV") for xylene.[26]
At the outset, it should be noted that Caravanos did not actually read a single article as part of his literature survey. Rather, with the exception of the ACGIH TLV documentation, he only read abstracts of articles retrieved from computer searches of MEDLINE and other medical databases. The court has grave doubts as to whether this constitutes a reliable methodology for researching medical evidence in support of an opinion on causation. While reading abstracts, no doubt, plays a role in medical research, presumably that *189 role is simply to identify articles that are worth reading in full in much the same way that headnotes and annotations are used in legal research. It is a place where research starts, not where it ends. The synopsis of a medical article given in its abstract will, of necessity, fail to include details regarding the methodology and conclusions of the summarized study that may attenuate or even destroy its relevance to the issue in question.
The present decision to exclude Caravanos's opinion on general causation, however, is not based exclusively on his disturbingly cursory research, for a review of the abstracts themselves reveals that they lend no support to his conclusions on the causal connection between acute or subacute exposure to xylene or other organic solvents and the chronic CNS and PNS symptoms alleged by Mr. Amorgianos. These articles all relate either to acute intoxication or eye irritation, or to substances other than xylene. See infra Appendix tbl. 3.
When asked how he extrapolated his conclusion regarding chronic effects of acute or subacute xylene exposure from these abstracts, Caravanos stated that he analogized from the fact that single, high dose exposures to other chemicals, such as lead, can cause irreparable damage to the body. (See Caravanos Dep. at 196.) As an industrial hygienist, Caravanos is, no doubt, qualified to testify to health risks associated with particular workplace chemicals that are generally accepted in the medical community; his profession requires such expertise. However, as is apparent from the foregoing review of the medical literature cited by plaintiffs' experts, the hypothesis that acute or subacute exposure to xylene can cause permanent CNS and PNS deficits has not obtained such status in the relevant scientific communities. Instead, plaintiffs' general causation hypothesis lies at the frontier of toxicological research, and Caravanos who is not a medical doctor, is not a toxicologist, is not a neurologist, and is not a biochemist, (see id. at 5-14, 20-21) is simply not qualified to reliably extrapolate from what a single dose of lead can do to the body to what a single dose of xylene can do to the body. His extrapolation is, therefore, only that of an educated layman. It is not offered by "an expert [qualified] by knowledge, skill, experience, training, or education," Fed. R.Evid. 702, and it will not assist the jury in determining the issue of causation in this case.
The only remaining basis of Caravanos's opinion on general causation, then, is the temporal connection between Mr. Amorgianos's alleged exposure in this particular case and his alleged onset of chronic CNS and PNS symptoms. (See Caravanos Dep. at 198-200.) However, no reliable conclusion on general causation can be drawn from a temporal connection in a single, anecdotal case. See Washburn, 2000 WL 528649, at *2, 213 F.3d 627 (citing Cavallo v. Star Enter., 892 F. Supp. 756 (E.D.Va. 1995), aff'd in relevant part, 100 F.3d 1150 (4th Cir.1996); Conde v. Velsicol Chem. Corp., 804 F. Supp. 972, 1023 (S.D.Ohio 1992), aff'd, 24 F.3d 809 (6th Cir.1994)).
For all the foregoing reasons-the lack of support in the cited medical and industrial hygienic literature, the fact that Caravanos did not read those articles, his lack of the educational qualifications necessary to make an extrapolation from the effects of lead and other substances on the body, and his reliance on temporal connection, as well as the facts that Caravanos has done no research of his own on the effects of xylene on the human nervous system, (Caravanos Dep. at 19), and that he developed his opinion for the purposes of litigation and has not subjected that opinion to the *190 scrutiny of peer review, (id. passim) Caravanos's opinion on the chronic effects of acute or subacute xylene exposure is neither competent nor reliable and is, therefore, inadmissible under Rule 702.
2. Propylene Glycol Monomethyl Ether
In his deposition, Caravanos opined that propylene glycol monomethyl ether ("PGME") may have also contributed to the causation of Mr. Amorgianos's alleged illness, though, in his opinion, xylene was "probably the dominant factor." (Id. at 150-152.) Caravanos's suspicion regarding PGME appears to be based on the fact that one of the thinners used on the project, Epolon Reducer 145, consists of fifty-two percent PGME. (See id. at 77.) However, there is not a single reference to PGME, or any other ether, in the abstracts cited by Caravanos. See infra Appendix tbl. 3. Caravanos's methodology with respect to his PGME general causation opinion, therefore, appears to be based solely on post hoc ergo propter hoc reasoning that Mr. Amorgianos became ill, PGME was present in the paint products he used, hence PGME can cause such illness. Again, a causal opinion based solely on a temporal connection between exposure and onset of illness in a single case is not epidemiologically reliable. See Washburn, 2000 WL 528649, at *2, 213 F.3d 627. Caravanos's opinion on PGME is, thus, an ipse dixit in its purest form. Accordingly, to the extent that Caravanos intends to testify at trial that PGME, or PGME in combination with xylene, can cause the types of chronic neurological problems plaintiffs allege, his opinion on the issue is also excluded under Rule 702.
G. Summary
As was noted at the outset of this section, the issue here is not whether exposure to some organic solvent in some amount and for some duration can cause some adverse CNS or PNS effect. The primary focus in the preceding evaluation of plaintiffs' experts' opinions has, therefore, been whether the types of exposures and the types of symptoms reported in the literature cited by plaintiffs' experts are sufficiently similar to the facts of this case to make their opinions on general causation in this case reliable. The articles cited by plaintiffs' experts do support an association between long-term exposure to a variety of organic solvents (not necessarily including xylene) and certain symmetrical, clinically testable, but subjectively unnoticeable sensory or motor deficits and neurasthenic conditions, whose onset is insidious and whose permanence is unknown. However, from these articles, plaintiffs' experts extrapolate to the conclusion that subacute exposure to high doses of xylene in particular can, as a general matter, cause sudden, permanent sensory and motor deficits of crippling severity and asymmetrical distribution, as well as disabling cognitive and behavioral effects, that can persist unchanged for three years or more. On these facts, there is simply too great an "analytical gap," Joiner, 522 U.S. at 146, 118 S. Ct. at 519, between the studies on which plaintiffs' experts rely and the conclusions they draw from those studies for their opinions to be reliable.
Moreover, with the exception of Dr. Moline, who treated Mr. Amorgianos prior to this litigation, each of plaintiffs' experts developed this hypothesis in the course of this litigation. And none of plaintiff's experts, including Dr. Moline, have since tested this hypothesis in any way or subjected it to peer review. Instead, plaintiff's experts have aired their hypothesis only in the courtroom and have elected not to share their ideas on this subject with their peers in the medical and industrial hygienic communities.
*191 For all these reasons, the methodology employed by plaintiffs' experts (i.e., extrapolation from existing studies) has not been reliably applied in this case. Accordingly, their opinions are not based on "scientific ... knowledge" and will not assist the jury in determining the issue of causation in this case. The expert testimony of Dr. Moline, Dr. Rutchik, and Caravanos on general causation as it relates to Mr. Amorgianos's alleged chronic illnesses will, therefore, be excluded under Rule 702.
In closing, it must be stressed that no judgment is made here as to the genuineness of any of plaintiffs' experts' opinions in this case. Rather, the ground for their exclusion is that, in light of the foregoing considerations, their opinions ultimately appear to be speculative. The surmise and conjecture of an expert, however, no matter how good his or her credentials, is still only that surmise and conjecture, not admissible evidence.
Conclusion
Defendant's motion to exclude plaintiffs' experts under Rule 702 is granted in part and denied in part.
Defendant's motion is granted in the following respects: (1) Caravanos, Dr. Moline and Dr. Rutchik will not be admitted to testify on the issue of general causation with respect to Mr. Amorgianos's alleged chronic neurological conditions; (2) Caravanos and Dr. Rutchik will not be admitted to testify as experts on the issue of the duration of Mr. Amorgianos's alleged exposure to xylene and other organic solvents; and (3) Caravanos will not be admitted to testify on the issue of the concentration of xylene or other organic solvents in the containment.
Defendant's motion is denied in the following respects: (1) Caravanos, Dr. Moline and Dr. Rutchik will be admitted to testify on the issue of the cause of Mr. Amorgianos's alleged eye irritation, nausea, fever, and other acute health conditions in the two- to three-day period after he ceased work on August 28, 1995, provided plaintiffs produce admissible expert evidence that the concentration of xylene in the containment on August 28, 1995 exceeded the OSHA PEL; and (2) plaintiffs may present otherwise admissible expert opinion evidence that is based on the estimated duration of Mr. Amorgianos's exposure to xylene and other organic solvents stated in plaintiffs' letter brief.
Because plaintiffs have not produced admissible expert evidence on the issue of general causation with respect to Mr. Amorgianos's alleged chronic illness and thus cannot sustain their burden of proof as a matter of law, defendant is hereby given leave to move forthwith for partial summary judgment on Mr. Amorgianos's claims with respect to his alleged chronic illness and his wife's derivative loss of consortium and services claim.
Finally, because the deficiencies in Caravanos's expert opinion as to the concentration of xylene appear to be ones that could potentially be remedied, plaintiffs are given leave to supplement Caravanos's expert report with respect to concentration. If plaintiffs elect not to do so and elect not to proffer an alternative expert opinion on the issue of concentration, defendant will be given leave to move for summary judgment on Mr. Amorgianos's remaining claims.[27]
Appendix
Table 1. Literature Cited by Dr. Moline. -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
*192
Supports Conclusion
that Subacute
Exposure
can Cause Chronic
Duration and/or Symptoms Described Authors' Comments CNS or PNS
Article Type Subjects Substance Dose or Tested and Conclusions Effects?
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
R.F. White & S.P. Review article Cites one case Organic solvents Unspecified Discusses WHO Effects on CNS No. Does not address
Proctor, Solvents example. 50-year generally classification and PNS of solvents xylene specifically.
and Neurotoxicity, old glazier with scheme for solvent-related are generally Does
349 The Lancet 32 years of exposure CNS fleeting and not discuss the
1239 (1997). to benzene, disorders resolve after exposure, duration or dose
toluene, zylol but in expected to produce
(xylene), and methylethylketone, some cases long-term the symptoms
who had never chronic exposure described,
used respirator or high-dose or associate particular
and had only acute exposures symptoms
been using can cause with particular
gloves for past permanent damage solvents.
two years. Suffered
from PN
and variety of
cognitive and
mood problems.
Subject had noticed
mood
changes for
"some years"
prior. One year
later, patient reported
"remarkable
improvement"
in mood and sensory
awareness,
though cognitive
(short-term memory)
deficits and
mood effects remained.
Two
years later, cognitive
deficits remained.
Only case example
noted presents
very different
exposure
history32 years
of unprotected
exposure to a
variety of organic
solvents other
than xylene.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Edward L. Baker, Review article N/A Organic solvents 9-10+ years PN, CNS (memory, Pathogenesis best No. Studies cited
Organic Solvent generally mood) deficits. understood with in support of conclusions
Neurotoxicity, 9 respect to n-hexane with respect
Ann. Rev. Public and methyl n-butyl to chronic
Health 223 (1988). ketone; exposure involve
these toxins can individuals with
cause a distal axonopathy 9-10 or more
resulting years of exposure
in symmetrical to a variety of solvents.
distal sensory loss Does not
and weakness. discuss the effects
of short-term exposure
(3-30
days) to xylene or
any other organic
solvent.
"[E]pidemiological
studies to date
confirm the occurence
of dose-related
impairment
in central-nervous-system
dysfunction
among individuals
chronically
exposed to a variety
of organic solvents.
... In some
cases, deficits appear
to persist for
significant periods
after exposure
ceases."
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
A.T. Fidler et al., Cross sectional Subjects: 101 Paint 101 painters See next column. Consistent positive No. Authors conceded
Neurobehavioural study with control currently exposed worked an average association was observed they were
Effects of Occupational group using self-reported construction and age of 18 years, between unable to associate
Exposure questionnaires maintenance with 30.6 weeks most measures of various exposure
*193
to Organic and painters. of work in the exposure and the indices with
Solvents among "eight tests of a last year, and 13 occurrence of neurotoxic objective neuro-behavioral
Construction computer administered days of work in symptoms, deficits.
Painters, 44 Brit. neuro-behavioral the last month. notably dizziness, Range of
J. Ind. Med. 292 evaluation Used an exposure nausea, fatigue, acute symptoms
(1987) system." index based on problems with arm was reported, but
rates, frequency, strength, and feelings study did not indicate
painting method, of getting whether
use/nonuse of "high" from chemicals these were symptoms
respirator, ventilation. at work. Associations felt during
The resulting with exposure work or after
index was were found work, and average
intended to measure with the neurobehavioral respondent
"average evaluation had worked for 13
lifetime paint system tests of days in last
use." symbol digit substitution month, and 30
and digit weeks in last
span; however, no year, i.e., currently
consistent pattern exposed painters.
of effect on neurobehavioral Authors did
function not study PNS effects.
was observed.
This pattern of
neurotoxic symptoms
without clear
evidence of function
deficit is consistent
with the
type 1 toxic CNS
disorder [organic
affective syndrome]
as classified
by WHO (as
opposed to WHO
type 2 [mild chronic
toxic encephalopathy]
and WHO
type 3 [severe
chronic toxic encephalopathy].
Controls: 31 dry Authors conceded
wall tapers.. their "inability to
demonstrate" the
hypothesized effects
on neurobehavioral
function.
Attempted to control
for alcohol,
nicotine, caffeine
consumption as
well as lead exposure.
Authors ultimately
discarded the
control group results
because the
two groups were
found not to be
sufficiently comparable
in age,
education and alcohol
consumption
to permit
meaningful comparison
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Lisa A. Morrow Uncontrolled Subjects: 22 occupational Unspecified mixture Mean length of See next column. 20 of 22 men No. The workers
et al., A Distinct case-series report. medicine of organic exposure was 7.3 showed scale involved in the
Pattern of Personality patients, solvents years (SD = 6.5 scores that deviated study had been
Disturbance without prior history years). Dose unspecified. by two standard exposed for mean
Following of neurological deviations of 7.3 years and
Exposure to Mixtures or psychological from the norm. had been exposed
of Organic disorder. After performing a to a variety of solvents,
Solvents, 31 J. regression analysis, including,
Occupat'l Med. authors found as the reported
743 (1989). a statistically significant case history indicates,
association solvents,
between duration such as TCE, that
of exposure and are not ingredients
MMPI scores corresponding in paint. In
to addition, the fact
mental confusion, that there was no
feelings of alienation, significant difference
unusual between the
thoughts and psychological scores of workers
turmoil. who had one or
No significant differences more high-dose
were exposures and
found between the those who had
scores of patients none, indicates
who had suffered that the causal
at least one "high factor at work, if
dose" accidental any, is duration of
exposure and chronic exposure,
*194
those who had not. not the occurrence
And no dose-response of acute exposures,
relationship such as
was found between those alleged by
duration of plaintiffs. Finally,
exposure and the small size
MMPI scores for of the study
the depression group and the
scale and no significant fact that it was
association composed entirely
for the social withdrawal of subjects who
or social had already presented
introversion scales. with clinical
symptoms
rather than a representative
cross-section
of exposed
workers further
attenuates the
weight of the results
obtained.
See Reference
Manual, supra,
at 138-39.
Administered the One case history
Minnesota Multiphasic reported: 42-year
Personality old machine
Inventory maintenance operator
(MMPI). who had
been exposed primarily
to trichloroethylene
(TCE),
a degreasing
agent, for 14
years, 3-4 times a
week, 3-4 hours
at a time in a
closed shop without
gloves. The
man had first begun
feeling
"strange" while
he was working
around TCE and
reported trouble
sleeping, incoordination,
visual disturbances,
personality
changes
and depression.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
P. Gregersen et Cross-sectional Subjects: 65 Danish Primarily white Mean exposure: Tested for acute Exposed workers No. Authors
al., Neurotoxic study with control workers currently spirit, perchoroethylene, 12.9 years (SD = symptoms (fatigue, had more symptoms found no statistically
Effects of Organic group. Aimed at exposed to toluene 9.5 years). Degree dizziness, of intellectual significant
Solvents in Exposed determining organic solvents and styrene. of evaporation, memory loss, impairment, poorer association between
Workers, 4 dose/response relationship (10 painters, 10 marked; sleep disorder, performances in solvent exposure
Am. J. Ind. Med. for dry cleaners, 33 ventilation, moderate; mood changes, psychological tests, and PN.
201 (1984) CNS and PNS effects. film developing, 73.1% of etc.) and objective and more often Acute CNS effects
12 polyester boat work was with inadequate signs (muscle signs of cerebral (dizziness,
builders). ventilation; strength, reflex, astenopia [a disturbance mood changes,
frequent coordination, gait, of the visual cognitive deficits)
possibility of skin diadochokinesis, function were observed in
absorption; 57/65 motor signs and caused by organic currently exposed
never wore symptoms of PN brain damage]. workers, but authors
masks. (1 to 8 scale), vibratory "Symptoms and declined to
thresholds, signs of peripheral reach a conclusion
touch and neuropathy occurred as to whether
pinprick tests; more frequently such effects were
psychological in the exposed irreversible or
tests for learning/memory, workers who transient, citing
concentration, also had a generally the inherent limitations
abstraction. higher VPT, of a cross-sectional
but the differences study.
were not statistically
significant."
Solvent exposure
and neurotoxic
signs and symptoms
were mildly
correlated in the
study group.
Such dose-effect
correlations have
previously been
proved only in a
few epidemiological
studies. This
warrants reevaluation
of the risk of
developing toxic
encephalopathy
during prolonged
exposure to solvents.
*195
Tests were conducted Controls: 33 After correction In addition, there
in the unexposed electricians for age, alcohol are two major
workplace. and warehousemen. and head injuries, problems of fit
there was a significant between the Gregersen
correlation study and
between exposure the facts of this
and the combined case. First, the
neurological and mean duration of
neuropsychological exposure for the
findings. But study subjects
there was no significant was 12.9 years,
correlation whereas plaintiffs
between exposure are claiming intermittent
and neurological exposure
findings alone, or over a
exposure and neuropsychological course of five
findings alone. weeks. Second,
only ten of the
sixty-five study
subjects worked
with paint.
Moreover, those
ten were exposed
primarily to
white spirit not
xylene in an
amount estimated
at three to four
times the TLV.
The study group
also included ten
dry cleaners who
were exposed primarily
to perchloroethylene,
thirty-three film
developers who
were exposed primarily
to toluene,
and twelve boat
factory workers
who were exposed
primarily
to styrene.
Long term effect Groups were comparable "As in other cross-sectional
and acute effect in age, studies, it
tested. Acute effect history of brain is not possible to
measured by traumas and neurological state with absolute
testing workers diseases, certainty that the
after 40 hours of and alcohol consumption. demonstrated neurological
nonexposure on and neuropsychological
Sunday and then signs and symptoms
again at the end manifest a
of work on Thursday. chronic condition
or whether they
are reversible."
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Douglas H. Linz Uncontrolled 15 industrial Variety of organic Work site A: 3 Subjective symptoms: Results of this No. Authors relate
et al., Organic case-series report. painters in Oregon solvents factory workers between study confirm the case reports
Solvent-Induced who had who had used painters and non-painters, existence of chronic on existence of
Encephalopathy come to clinic for new paint booth significantly encephalopathy conditions in
in Industrial treatment (not a with ventilation more in organic solventexposed painters with exposures
Painters, 28 J. random cross-section). defect. One chronic cough, painters. of 3-4
Occupational worker had 5 headache, dizziness, Five painters had months to 24
Med. 119 (1986) years of exposure: sleep disturbance, sensorimotor peripheral years, who had already
the other 2 decreased neuropathy. presented
had 3-4 months coordination, abnormal ... This toxic themselves for
of exposure. taste or encephalopathy treatment. Authors
Each had 5-8 smell, personality ... was presumably only presume
weeks of exposure change, decreased caused by organic the causal
in the defective memory. solvent exposure connection. Does
paint booth. rather than not specify the diagnoses
2-3 months since some other factor of the
last exposure at associated with industrial two patients with
time of examination. painting." short term exposure
(3-4
months).
Physical exams, Painters were Work site B. Factory. Physical exam:
blood tests, neuropsychologic compared with Paint mild distal neuropathy
evaluation. "control group" of booths with inadequate with reduced
30 non-painter ventilation. two-point
workers/patients Air supply discrimination in
with respect to respirators used 4/15 painters (does
subjective symptoms. only for 1-2 years not indicate which
before exam. 4 ones).
workers with 4
13 years of exposure,
and 4 -30
months since last
exposure.
Baseline performance Work site C. Factory. Cognitive, sensory
of group Paint booths and motor deficits
on neuropsycho- with poor ventila- in compari-
*196
logical tests was tion, poorly fitted son with general
assumed to be average respirators with norms. Mood
(e.g., insufficient filter problems. "Seven
IQ=100); authors changes. Air painters [authors
assumed supply respirators do not say
that the painters only used for last which] underwent
were not below or 1-2 years. 8 evaluation for rehabilitation
above the average workers with 3.4 at another
of the general to 24 years exposure, institution
population. and 2-32 approximately 1
months since last year after the initial
exposure. Ambient evaluation
concentration and in the absence
of solvents at of further
the work sites organic solvent
was not measured. exposure. At
that time clinical
neurologic examinations
were normal
in all subjects,
but four
manifested cognitive
impairment
and one was regarded
as unusually
mentally
slow. Abbreviated
neuropsychologic
tests showed
that all had impairment
of visual-spatial
perception,
regulatory
function, short-term
memory, abstraction
ability,
and motor skills."
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Edward L. Baker Review article N/A Various organic "[H]eavy expos[ure] See next column. "In summary, existing No. Authors only
et al., The Neurotoxicity solvents over a studies indicate associate PN with
of Industrial period of months the occurrence Mn BK and n-hexane,
Solvents: A to years." of defined not xylene
Review of the Literature, syndromes of peripheral or other organic
8 Am. J. neuropathy solvents.
Ind. Med. 207 and toxic encephalopathy Supports toxic encephalopathy
(1985). that (CNS) with onset
occur in individuals after "periods of
heavily exposed excessive exposure,"
to solvents but does
over a period of not specify the
months to years. necessary
An important recent dose/duration other
study of individuals than summary
chronically sentence which
exposed below the indicates the various
TLV failed to conditions reported
demonstrate significant in the literature
nervous generally
system impairment. have occurred after
Peripheral a "period of
neuropathy occurs months to years."
as a result of axonal
degeneration
caused by exposure
primarily to
the hexacarbon
solvents n-hexane
and methyl n-butyl
ketone....
[F]urther research
is necessary to
evaluate the potential
for peripheral
neurotoxicity in
groups exposed to
solvents other than
n-hexane or methyl
n-butyl ketone.
The accumulated
evidence
supports the occurrence
of a syndrome
of toxic encephalopathy
caused by excessive
exposure to
organic solvents in
trades such as
painting and boat-building.
This
syndrome is characterized
by memory
disturbances,
impaired psychomotor
function,
impaired verbal
*197
abilities, and disturbances
of mood.
The onset of such
behavioral complaints
occurs during
periods of excessive
exposure
to solvents and
persists after exposure
has ceased.
A nonspecific manifestation
of early
solvent toxicity has
been referred to
as "neurasthenic
syndrome," which
manifests primarily
as fatigability,
irritability, depression,
and episodes
of anxiety. Although
obviously
caused by many
other etiologies,
this constellation
of symptoms occurs
frequently in
individuals with
excessive exposure
to solvents in the
absence of more
pronounced disruptions
of neuro-behavioral
function.
Follow-up
studies of patients
with solvent-induced
toxic encephalopathy
have
shown persistence
of functional impairment
years after
removal from
solvent exposure."
(Emphasis added.)
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Edward L. Baker Review article N/A Organic solvents N/A Reviews evidence A characteristic No. Author states
& Lawrence J. generally related to the distal, symmetrical that no dose-response
Fine, Editorial, WHO syndrome sensimotor peripheral relationship
Solvent Neurotoxicity: categories. has been or pathogenetic
The clearly demonstrated explanation
Current Evidence, following has been established.
28 J. Occupat'l exposure of humans PN has
Med. 126 and animals been shown only
(1986) to several specific with respect to
solvents: n-hexane, particular solvents-n-hexane,
methyl-n-butyl-ketone methyl n-butyl
(MBK) and ketone, and carbon
carbon disulfide." disulfide, and
it is symmetrical
in nature. Only
scientifically convincing
evidence
of chronic toxic
encephalopathy
(CNS) comes
from studies on
the deliberate
abuse of toluene.
(1) Acute intoxication "Less convincing
with no evidence exists
lasting effects is linking mixed solvent
well-established. exposure to
clinically significant
peripheral
nerve disorders.
... [I]ncreased
risk of
PNS disorders
appears in certain
populations
[exposed to solvent
mixtures,
such as painters
and lacquerers].
However, the relationship
of
those disorders to
specific agents
has not been elucidated.
Furthermore,
clear distinctions
between
clinical and sub-
*198
clinical neuropathy
have not
been made in all
studies, rendering
the interpretation
difficult. In
studies of currently
exposed
groups, the rates
of PNS toxicity
have been less
than CNS effects."
(2) Acute toxic "The underlying
encephalopathy pathogenesis of
"is well recognized toxic encephalopathy
as an effect is unclear and
of excessive exposure requires further
to lead, mercury study. The lack of
and other consistent dose-response
toxic agents. The relationships
condition has not in chronic
been described as epidemiologic
a characteristic studies makes it
finding in excessive difficult to determine
short-term whether current
solvent exposure." exposure to
levels below accepted
PELs is
truly hazardous.
In fact, a recent
U.S. study failed
to observe consistent
neurobehavioral
deficits and
current exposure
documented at levels
below relevant
PELs."
(3) Organic affective "As yet unresolved
syndrome are the difficult
(duration: days issues of
or weeks; no sequclae) dose-response relationships
("a reversible and pathogenetic
mood disorder") mechanisms
occurs in [for CNS
individuals with and PNS effects.]"
chronic solvent
exposure
(dose/duration unspecified).
(4) Chronic toxic
encephalopathy
(mild or severe)
(mood changes,
short term memory
and psychomotor
impairment)
"has been reported,"
"The most
convincing scientific
evidence derives
from studies
who have abused
solvent-containing
products [e.g.,
model glue]."
Other studies involving
exposed
populations have
shown varied results
whose interpretation
is difficult.
"Further
case-referent
studies are needed
to clarify the
results of those
two investigations."
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Anna Maria Seppalainen. Cros-sectional 102 car painters Mixture of solvents Exposure ranged Abnormal EEGs "The fact that No. Tends to support
Neurophysiological study with control randomly selected in paint, from 1 to 40 years in 32 car painters slight peripheral conclusion
Effects group of age-matched from 27 garages principally toluene, (mean 14.8 years, and 37 referents. nervous lesions that organic solvent
of Long-Term railroad in Helsinki. xylene, butyl SD 8.5 years). 26 car painters could be shown in exposure
Exposure engineers. acetate and white Concentration in had complex of a group of car may cause PN,
to a Mixture of spirit. the workplaces CNS symptoms; painters in comparison but mean exposure
Organic Solvents, average 31.8% of 12 referents had to railroad was 14.8
4 Scand. J. Work the Finnish TLV, same complex. engineers indicates years, and subjects
Environ. & with concentration 46% of car painters that even at a relatively were tested
Health 304 (1978) of specific with syndrome low level of as few as 16
solvents ranging had abnormal exposure a mixture hours since last
from 4 to 212% of EEG, while of organic solvents exposure. Thus,
the TLV. only 26% of the may affect does not support
*199
car painters without the nervous system conclusion that
the syndrome in an undesirable short-term exposure
did. Referents manner." (3-30 days)
did not show this can cause permanent
tendency. Abnormally PNS effects.
slow Nor does study
motor and sensory support the
nerve conduction claimed chronic
velocities CNS effects,
were found in 12/59 since, based on
car painters but the EEG results,
0/53 referents. authors found no
Findings showed evidence of significant
"slight" positive difference in
signs of slowed CNS function.
nerve conduction
velocities and no
increase in EEG
abnormalities in
comparison with
referents.
EEGs taken of all NCV studies The "mainly low to
subjects; EMGs showed abnormalities moderate" exposure
taken of 59 painters in the maximal of the car
and 53 referents motor and painters did not
with similar sensory velocities "separate the car
age distribution. and motor distal painters from the
velocities in 20% reference population
of car painters with respect
tested, but none to EEG results."
of referents. But "No definite EEG
the "abnormalities features separated
were slight if the car painters
concluded from from the railroad
the fact that the engineers."
mean conduction
velocities of the
car painters did
not differ statistically
significantly
from the engineers."
Tests administered
at least 16
hours after last
exposure.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Table 2. Literature Cited by Dr. Rutchik.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Supports Conclusion
that Subacute
Exposure
Duration and/or Symptoms Described Authors' Comments can Cause Chronic
Article Type Subjects Substance Dose or Tested and Conclusions Effects?
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Douglas N Uncontrolled case 15 affected employees Xylene Estimated exposure Headache, nausea, N/A No. No permanent
Klaucke et al., An report at community was up to vomiting, and injury noted.
Outbreak of Xylene hospital 700 ppm. dizziness, eye, Acute intoxication
Intoxication after fumes from nose or throat irritation. from acute exposure.
in a Hospital, 3 1 litre of discarded All subjects'
Am. J. Ind. Med. xylene entered symptoms
173 (1982) the ventilation resolved within 48
system. hours.
Mediation duration
averaged 36
hours, ranging
from 2 to 48
hours.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
R. Morley et al., Uncontrolled case 3 male painters, Xylene Exposure for 15 One man died, Authors suggest No. Ultra-high
Xylene Poisoning: report aged 54, 42, and hours to 10,000 with evidence of xylene might be dose exposure
A Report on 24, lost consciousness ppm xylene with lung, liver, and useful as an anesthetic. caused one death.
One Fatal Case and remained virtually no ventilation brain damage. No lasting effect
and Two Cases of undiscovered and no respirators. The other two recovered, reported in the
Recovery After for 18.5 showing other two men.
Prolonged Unconsciousness, hours in a closed only transient liver
3 compartment inside damage, and in
Brit. Med. J. 442 a ship which one case, temporary
(1970). contained xylene impairment
vapor. Compartment of renal function.
was approximately
17' (L) ×
17' (W) × 4.67'
(H) feet with virtually
no ventilation.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Roberta N. Hipolito, Uncontrolled case 5 laboratory technicians Xylene Exposure between 58 year-old woman N/A No. Anecdotal reports
Xylene Poisoning report who 1.5 and 18 with 15 years by a laboratory
in Laboratory worked with xy- years. exposure in 6×8 technician,
*200
Workers: lene in unventilated foot unventilated not a scientist or
Case Reports and rooms. room. After 11 doctor. Only one
Discussion, 11 years, she began report mentioned
Lab. Med. 593 to complain of permanent damage:
(1980) headaches, LG fever, a worker
dyspnea, with 15 years of
flushes, nausea exposure whose
and vertigo. After symptoms began
15 years she 4 years earlier.
collapsed with severe
chest pain
and abnormal
ECG. Has not
worked since.
Disabled, low in
energy, and capable
of only limited
self care.
66 year-old woman
with 6 months
of constant xylene
exposure reported
cyanotic
hands, fever,
heart racing,
general malaise.
After she was removed
from xylene,
"she felt
fairly well although
not completely
recovered."
35 year old woman
with 4 years of
exposure began
to experience
chronic headache,
mental "fuzziness,"
chest pains
and extreme fatigue.
No discussion
of any residual
effect.
A fourth woman
complained of
headache, fatigue
and low WBC
count. After cessation
of exposure,
she reported
being in "good
health."
A fifth woman
complained of
chest pains after
6 months of exposure
in unventilated
room. After
moving her
work station away
from xylene
source, "her general
health is
greatly improved."
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Kaj Husman & Cross sectional 102 male car Various organic Exposure ranged Statistically significant Dizziness, unusual No. Although the
Pauli Karli, Clinical study with nonexposed painters and 102 solvents from 1 to 40 years difference tiredness, concentration authors found
Neurological reference age and sex (mean 14.8, SD in frequency of difficulties, significantly
Findings among group. matched locomotive 8.5). psychoorganic and impaired worse sensory
Car Painters Exposed engineers syndrome memory are the findings and subjective
to a Mixture and assistants. (changes in judgment, most commonly reported neuropsychological
of Organic comprehension, symptoms signs,
Solvents, 6 Scand. memory, attention, of workers who the resulting abnormalities
J. Work Environ response are chronically exposed. were
Health 33 (1980) time), decrease in subclinical in nature,
sense of touch and appeared
and pain, increase in painters
in vibratory who had a
threshold. 65/102 mean exposure of
painters had decreased 14.8 years.
sense of
vibration in lower
extremities, compared
with 25/102
referents.
Blind neurological These are the In 12/102 pairs, the On objective testing,
exam. Range of same subjects as painter had greater "[o]nly few
motion, reflexes, in Seppalainen signs of organic pathological findings
sense of light (1978), summarized syndrome, and appeared, and
touch and pain, in Table 1, in 36/101 pairs the no statistically significant
vibratory thresh- supra. exposed subject differ-
*201
olds, and muscle had more pathological ences, between the
strength tested. logical sensory groups with respect
findings. to cerebellar
and extra pyramidal
system, the
cranial nerves, and
peripheral motor
and sensorimotor
functions."
16 painters had a "[N]o signs were
worse sense of found that indicated
pain in the hand lesions in the
than their referents. peripheral motor
Sense of vibration system."
was more
affected in peripheral
areas of
both the upper
and lower extremities
than
among the referents,
especially in
lower extremities.
"Pathological findings
... for the
sense of light
touch occurred
more frequently in
the exposed group
only in regard to
both hands, and
not in the lower
extremities or the
trunk."
Changes in vibratory
threshold
seems to be the
most sensitive
function to suffer
in long-term exposure.
Although
these were "clear
signs of CNS and
PNS lesions," they
were not clinical in
nature: "they
were not ill in the
clinical sense."
Although these
were "clear signs
of CNS and PNS
lesions," they were
not clinical in nature:
"they were
not ill in the clinical
sense."
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Anna Maria Seppalainen, See Table 1. supra.
Neurophysiological
Effects
of Long-Term
Exposure
to a Mixture of
Organic Solvents,
4 Scand. J. Work
Environ. &
Health 304 (1978)
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Margit L. Bleecker Cross-sectional 187 workers in Toluene, xylene, Total average exposure See next column. "Linear regression No. Authors reject
et al., Dose-Related study designed to two paint factories methyl ethyl ketone, for the analysis controlling an association
Subclinical determine the occurrence and other various solvents for several between sub-TLV,
Neuro-behavioral of painter's aliphatic and aromatic considered confounding variables chronic exposure
Effects of syndrome hydrocarbons. ranged from 0.4 demonstrated and organic
Chronic Exposure (i.e., deficits in ppm to 31.2 ppm. significant correlations affective disorder.
to Low Levels memory, concentration, between increasing Dose-effect
of Organic fatigue, exposure relationship between
Solvents, 19 Am. personality to mixed organic certain
J. Ind Med. 715 changes, headache, solvents and neurobehavioral neurobehavioral
(1991) irritability). performance test results was
for vibration seen only in
threshold workers with
and several neuropsychological more than 10
tests. Dose-related years of exposure,
effects of but the effects
chronic solvent were all subclinical.
exposure on neurobehavioral No signs of
outcomes peripheral neuropathy
(all subclinical) were observed
were in any of
shown, but "typical" the subjects.
symptoms
*202
characteristic of
painter's syndrome
were not
found."
Administered Employ-ment "When an association
medical psychological ranged from 3.5 between a toxic
questionnaires, months to 36 exposure and a
neuropsychological years with a health outcome is
batteries, mean of 15 years. observed, the presence
vibration of a dose-response
threshold testing. or dose-effect
relationship is
of critical importance
in establishing
whether the
association is causal."
Testing occurred Only the 176 Criticizes other
at the beginning workers who had studies that have
of a work shift. at least 5 years of found associations
employment were for not controlling
subjected to the for confounding
neuropsychiatric variables, such as
and neuropsychological intelligence.
tests.
Regression analysis "Painter's syndrome
included confounding due to
factors chronic low-dose
of age. vocabulary solvent exposure is
score, alcohol, reported usually to
smoking, race, develop following
work shift, and at least 9 years of
plant location. exposures, with
incipient cases
identified after 3
years of exposure."
"[S]olvent-induced
central nervous
system dysfunction
is thought to
require 5-10 years
of exposure."
Study found statistically
significant
dose-response relationship
only on
certain neurobehavioral
tests: digit
symbol substitution,
serial digit
learning, reaction
time, "Trails A",
"Trails B", and
"Toe."
"[N]o correlation
was found between
these outcome
measures and responses
on the
symptom questionnaires
or neuropsychiatric
evaluation.
Thus, these
were subclinical
findings."
Subjects were divided
into those
with more than 10
years of work and
those with 10 or
fewer years of
work. Significant
effects in these 6
areas were found
only in the workers
with more than
10 years of exposure.
Disputes previous
painter's syndrome
studies: "`[T]ypical'
subjective
symptoms of central
and/or peripheral
nervous system
damage were
absent in the present
population."
Authors rejected
"healthy worker
effect" as an explanation
for the absence
of findings
*203
based on personnel
records that
showed less than
5% per year turnover.
`No study subject
had symptomatology
compatible
with a peripheral
neuropathy."
"[Vibration threshold]
changes,
which were small
and not associated
with symptoms,
may never develop
into a clinical neuropathy."
"Analyses showed
that the dose-effect
in these neuropsychological
tests
was not the result
of acute solvent
exposure but required
chronic exposure
to low levels
for more than
10 years."
"The association of
a psycho-organic
syndrome with exposure
to chronic
levels of solvent
was not supported
in this study.
Dose-related subclinical
neurobehavioral
effects in
the central and peripheral
nervous
system were demonstrated."
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Stig-Arne Elofsson Cross-sectional Subjects: 80 car Toluene was most Sub-TLV exposure. Statistically significant "It appears from No. To the extent
et al., Exposure study with control or industrial common solvent, differences the results that significant neurologic
to Organic group. painters (in 20 but xylenc, TCE, were found the solvent-exposed effects were
Solvents, 6 Scand. different shops). and white spirit indicative of neurasthenia, workers had found, they were
J. Work Environ. were also common. reaction a higher frequency subclinical in
Health 239 (1980) time, manual of neurological and magnitude; as
dexterity, perceptual psychiatric symptoms authors note, the
speed, short-term than their referents." exposed group
memory. consisted of "people
No significant differences in full daily
in verbal, work." Moreover,
spatial or no dose-response
reasoning tests. relationship
Significant differences could be
found in the found. The study
majority of neurophysiological did not specify
parameters the duration of
measuring exposure, and
peripheral since it involved
nerve functions. currently exposed
workers cannot
warrant a conclusion
as to whether
the observed
effects would persist
after cessation
of exposure.
Psychiatric interviews, Controls: two Use of preventive "In comparison However, the neurological
psychometric matched referent equipment and with both reference results,
tests, groups of 80 non-exposed, work conditions groups, the even where significant,
neurological, neurophysiological age- and were factored into exposed group were subclinical:
and opthalmological education-matched an exposure index. had a clearly "[W]e found
tests and CT electronics Only those higher symptom statistically significant
scans. plant workers. 80 painters with score for 11 items difference between
the highest indices (inner tension, irritability, the exposed
out of 156 initial fatigability, group and, in particular,
subjects were aches and reference
examined. pains, learning group 2 that indicated
problems, short- a reduced
and long-term function of peripheral
memory problems, nerves ....
nausea, epigastric However, the differences
pain, were
headache, and ... small, and all the
precision movement). mean values were
Statistically within normal
significant limits."
differences were
found for five ad-
*204
ditional items
(worrying over
trifles, concentration
difficulties,
vertigo and dizziness,
dyspnea,
and mood lability).
The most
pronounced differences
were observed
for memory
problems,
headache, and fatigability."
Subjects were examined Range or mean "The psychiatric The painters "were
over two duration of exposure investigation fully fit for work,
consecutive days not given. showed that psychiatric and there was no
during the work complaints reason to expect
week. were considerably any grave clinical
more abnormalities
common among among them."
painters than
among [referents]."
Unexposed only Psychological "We have not been
for 18 to 24 hours exam showed statistically able to demonstrate
before testing. significant a correlation
"We therefore do differences between degree
not know to what in memory, perceptual of exposure
extent the observed speed, and extent of effect
effects manual dexterity, (dose-response correlation)."
were or were not and simple reaction
reversible." time. But
"it was not possible
to demonstrate
any effect
or correlation
that indicated a
dose-response relationship."
Authors
hypothesize
the healthy worker
effect as an explanation
of these
"somewhat contradictory"
results.
Neurologic: Significant
differences
were found
for Romberg's
test, finger to
nose test, finger
to finger test and
finger tremor.
But in "all cases
the findings were
minor," and
"must be regarded
with caution"
because the examinations
were
performed by
"two physicians,
for whom the distribution
of exposed
and reference
subjects was
unequal."
No significant differences
in EEGs
found, and authors
note that
other studies that
did find significant
differences
in EEGs, did not
find a dose-response
relationship.
Significant difference
found in the
function of the
purely sensory
sural nerve distally
on the lower
leg; but nothing
in arms.
Significantly
higher vibration
thresholds found,
but an "increased
vibration threshold
is not neces-
*205
sarily associated
with sensory
symptoms."
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Raymond Y. Cross-sectional 28 commercial Solvents in order Painters had an Significant differences Because of the No. Involves
Demers et al., Peripheral study with reference painters and reference of frequency were average of 30 in vibratory small sample workers with 30
Vibratory group. group of mineral spirits, years of painting threshold were size, "[l]arger years of exposure,
Sense Deficits 20 unexposed toluene, ketones, exposure. seen in the nondominant numbers are makes findings
in Solvent-Exposed boiler makers. and xylene. dominant great needed to establish only with respect
Painters, toe, the nondominant a dose-response to vibration
33 J. Occupational index toe, relationship threshold, and declines
Med. 1051 (1991) the nondominant between to posit a
index finger, the specific solvent dose-response or
fingers in combination, exposures in causal relationship
and the painters and resulting ship in light of
summary vibration vibration the small sample
scores for all sense abnormalities. size.
four digits. Causality
must also be
linked with specific
solvents."
Tested vibration
thresholds.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Frank J. Bove et Cross-sectional 93 construction Not specified. Mean years See next column. Explains peripheral No. Found only
al., Sensory study with reference painters and a worked = 18 neuropathy as subclinical deficits
Thresholds group. reference group years. 20 weeks follows: "The onset in vibratory sensation
among Construction of 105 healthy worked in last and early in group of
Trade Painters: construction and years, mean. 9 stages of the disease currently exposed
A Cross-Sectional industrial workers. days worked in are insidious. painters with a
Study last month, mean. Initial symptoms mean exposure of
Using New Methods such as numbness 18 years.
for Measuring and tingling occur
Temperature frequently in the
and Vibration lower extremities.
Sensitivity, 31 J. As axonal degeneration
Occupational proceeds,
Med. 320 (1989) symmetrical sensory
and motor
loss develops in a
`stocking-glove'
fashion."
Painters who had "The disease can
retired more than continue to progress
two years earlier for several
were excluded months after cessation
since "recovery of of exposure,
peripheral nerve but thereafter improvement
function can occur occurs,
within a few with all but the
years after cessation most severely affected
of exposure." regaining
all or most of motor
and sensory
function.
In severe cases,
neuropathy persists
for several
years after exposure
cessation."
Identifies as suspected
peripheral
neuropathic toxins
carbon disulfide,
methyl n-butyl ketone,
and arsenic,
but not xylene.
Notes that existing
studies with painters
and vibratory
thresholds have
found only subclinical
differences.
Results: no statistically
significant
difference in temperature
sensitivity
thresholds, but
significant correlation
found between
vibratory sensitivity
and lifetime exposure
and exposure
over past
month variables.
Abnormal results
on the neurologic
examination tended
to be among
relatively older
painters who had
*206
worked many
years but had
worked relatively
less than other
painters in the
previous year.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
M.W.M.M. Ruijton Cross-sectional 31 painters (11 of Spray painting Mean exposure Symptom questionnaire Results indicate No. Found primarily
et al., Neurobehavioral study with agematched whom had already with >50% xylene. 16.9 years (SD showed that complaints regarding symptomatic
Effects referents. complained 9.5). significant differences mood complaints
of Long-Term of illness) and 38 in mood changes, equilibrium in currently exposed
Exposure to Xylene referents. change, equilibrium, and fatigue painters
and Mixed fatigue, "solvent were more severe with a mean exposure
Organic Solvents related complaints." in painters than in of 16.9 years.
in Shipyard referents but were
Spray Painters, not related to the
15 Neuro Toxicology estimated life-time
613 (1994) exposure index.
Symptom questionnaire Respiratory and Neurological: significant "Limited information
designed skin protection velocity on the effects
to test for was used when difference in of exposure to xylene
organic affective spray painting in nerves of the leg. ... is available,
disorder, nerve confined spaces. which consists
conduction velocity mainly of
tests, and computerized symptomatology,
performance including fatigue,
tests. headache, irritability,
apathy, dizziness,
loss of appetite,
dry throat,
alcohol intolerance
and sleep impairment.
In the
present study
complaints regarding
fatigue, dizziness
and mood
changes ... were
prominent ....
Surprisingly,
memory complaints
and absentmindedness
are not mentioned
as part of the occurring
symptoms,
nor were they
found in the current
study."
Neurobehavioral: Cites another
significant differences study on xylene involving
only in two symmetrical
attention span PN.
tests.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Anna Maria Seppalainen Uncontrolled 107 patients already 55 of the subjects Mean exposure of 70/107 had abnormal "Nervous system No. Descriptive
et al., case-series report. diagnosed had been exposed 9.6 years for male EEGs, involvement was study of already
Neurophysiological with solvent poisoning to non-paint related patients; mean of though the abnormalities usually of mild degree, diagnosed patients,
and Psychological after longstanding solvents, principally 7.6 years for female were eg, no cases showing
Picture of exposure. TCE [degreasing] patients. slight in degree, of actual paresis slightly abnormal
Solvent Poisoning, and all in subjects were detected." EEGs and slowed
1 Am. J. Ind. perchloro-ethylene with "intermediate" NCVs and deficits
Med. 31 (1980) [dry cleaning] or "high" exposures. in certain attention
span tests in
men with a mean
of 9.6 years of exposure,
half of
them to chemicals
other than paint
solvents. No
dose-response relationship
was
found on the
NCV studies.
EEGs and psychological Exposure usually 17/31 men and 31/46 No relationship
battery near the Finnish women had at between the neurophysiological
on all subjects TLV. least one abnormally and neuropsychological
and NCS on 77 slow CV CV results
subjects. scores were not emerged: "Psychological
found to be correlated performance
with length scores in
of exposure or patients with abnormal
age. EEGs,
were not found to
be significantly
different from
those of patients
with normal
EEGs."
On neuropsychological Authors concluded
battery, that increased
*207
the mean scores frequency of abnormal
on digit span and EEGs indicates
digit symbol were toxic encephalopathy.
significantly lower
than the Finnish
average for
men, and similarities,
digit symbol,
picture completion
and block design
were significantly
lower than
Finnish average
for women.
"Although the correlations
between
the exposure level
and/or length of
exposure and neurophysiological
or
psychological findings
were relatively
weak, we think
that our findings
are related to the
occupational solvent
exposure....
It is possible that
the exposure level
is a more potent
determinant of the
effect than the
mere length of exposure
and that
repeated episodes
of high-peak exposures
may play a
major role in causing
the nervous
system effects."
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Anna Maria Seppalainen Uncontrolled follow-up 87 patients (40 21 exposed to Mean exposure EEG comparisons. Mentions "paresthesia, No. Authors of
& Mari study. men and 47 women) perchloro-ethylene was 10.7 years 26 clearly muscular this descriptive
Antii-Poika, Time previously diagnosed (perc) or (range 1-33). improved, 15 pain, and diminished follow-up study
Course of Electrophysiological with TCE; 53 exposed slightly improved, strength" as with no control
Findings for Patients chronic solvent to solvent mixtures; 28 similar (19 of possible effects of group expressly
with Solvent intoxication after 13 to both which were normal exposure. Cites state that the results
Poisoning: occupational exposure. solvent mixtures both initially 2,5 hexanedione; are only
A Descriptive and TCE or perc. and at follow-up), 2,5 hexanediol; n-hexane; "suggestive."
Study, 9 Scand. J. 14 slightly deteriorated, and methyl Subjects were exposed
Work Environ 4 moderately n-butyl ketone for a mean
Health 15 (1983) deteriorated. as suspect of 10.7 years.
On initial agents. Only 61% of the
exam and follow-up subjects were exposed
EEG abnormalities to xylene,
were and those that
"slight in degree." were, were also
"Severe abnormalities exposed to host of
were other chemicals.
rare." Authors disclaimed
ability to
relate the conditions
observed to
specific chemicals.
CNS and PNS effects
were noted
to be "slight" in
degree, often with
improvement "to
a normal or almost
normal
state" over time.
And no dose-response
relationship
was found.
EEGs and EMGs Mean age of subjects Solvent mixtures 54 patients EMG comparisons. No dose-response
performed 3 to 9 was 38.6 were mainly aliphatic stopped working 7 clearly improved, found: "The duration
years (mean 5.9 years at initial diagnosis hydrocarbons after the initial 24 slightly and level of
years) after initial (range (petroleum diagnosis; 33 continued improved, 18 exposure or the
diagnosis. 20-59). Original benzine), ethyl to work in similar, 22 slightly immediate termination
subjects numbered toluenes, and trimethylbenzenes. exposed conditions deteriorated, 2 of exposure
106: only "In most cases for different moderately deteriorated. after the diagnosis
87 came for reexamination. the patients had lengths of time, 5 "Polyneuropathy had no clear relationship
On also been exposed were still working of to the
initial exam, only to thinners, the at the time of the slight degree was prevalence, the
73/106 had EMGs. main component follow-up. the most usual type, or the time
of which was toluene finding." course of the EEG
and which or EMG findings."
usually also contained
methyl isobutyl
ketone, isobutanol,
and
ethylene glycol,
or sometimes pe-
*208
troleum benzine,
isopropanol acetone,
xylene, and
butyl acetate."
No control group. Some tendencies
were noted: patients
with exposure
to both solvents
and to perc
or TCE had more
neuropathic findings
than those exposed
to either
alone.
"The present
study is descriptive,
and only cautious
conclusions
can be drawn from
its results. The
main problems in
the evaluation of
the results concern
the uncertainty of
the initial diagnosis
of the patients
and the lack of a
control group during
the follow-up."
Results, either
where statistically
significant, should
only be considered
"suggestive."
Although some
have reported an
initial deterioration
during the
first 1 to 4 months
after exposure,
"[r]ecovery to a
normal or an almost
normal state
has been common
among patients
with occupationally
induced neuropathy."
"On the basis of
this study it is impossible
to define
selective differences
between the
effects of different
solvents."
"The present
knowledge on the
metabolic and
pharmaco-kinetic
mechanisms of
various solvents
singularly and in
combination is so
limited that these
differences are not
readily explained."
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Mari Antti-Poika, Report on the See Seppalainen See id. This article states At time of initial "The intoxication No. Same comments
Overall Prognosis same reexamination & Antti-Poika that at the initial diagnosis, 31 patients was slight in most as for Seppalainen
of Patients with of the same (1983), supra. exam, 11/87 patients had objective cases.... The & Antti-Poika
Diagnosed 87 patients in discussed had not been exposed clinical neurologic number of patients (1983), supra.
Chronic Organic in Seppalainen for 1-6 signs, with clinical polyneuropathy In addition,
Solvent Intoxication, & Antti-Poika months before diagnosis, whereas remaining in the authors noted no
51 Int'l (1983), supra. 3 for 7-9 56 had only present study was statistically significant
Archives of Occupational months, and 2 for subjective symptoms so small that the association
& Environ. 5-6 years. and neurophysiological trend cannot be between level
Health 127 or definitely evaluated." or duration of exposure
(1982) psychological and prognosis.
findings attributed Further,
to solvent intoxication. authors found no
Upon significant number
reexamination, of patients
the condition with PN of clinical
[taking neurologic severity.
and psychological
signs together] of
23 had improved;
43 remained unchanged;
and 21
had deteriorated.
This article discusses Upon diagnosis The prognoses
the results and reexamination, yielded by the
of an interview the most neurologic and
*209
and psychological common symptoms psychological examinations
exam, in addition were fatigue, correlated
to the EEGs and headaches, poorly with
EMGs discussed and memory disturbances. one another. No
in the 1983 article. The statistically significant
symptoms related correlation
to PNS were was found between
pain, numbness, the overall prognosis
and paresthesias and age, sex,
in the extremities. the duration and
Common CNS level of exposure,
disturbances were the termination of
psycho-organic exposure after diagnosis.
syndrome, cerebellar
disturbances,
disturbances
in gait and
station; in PNS,
sensory disturbances
and diminished
tendon reflexes.
NCVS
showed slow velocities;
psychological
tests
showed broad
range of disturbances.
"Considering the
limitations described
above, only
cautious conclusions
can be
drawn. However,
some trends can
be seen. Even
some of the mildest
cases of chronic
solvent intoxication
may stay
unchanged or even
deteriorate."
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Douglas H. Linz See Table 1,
et al. (1986) supra.
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Pall Orbaek et al., Cross-sectional 50 male paint factory Eight most common Exposed group Blood tests: Significantly CNS: Subjective No. Supports association
Effects of Long-Term study with age-and workers exposed solvents in selected for minimum lower symptoms of brain between
Exposure education-matched for 5-46 factory included of 10 years' blood cell counts, dysfunction were combination of organic
to Solvents in the referents. years (mean 18 xylene (80 ppm). employment in but no dose-response significantly more solvents
Paint Industry, years). All subjects Toluene was also solvent-handling relationship frequent among and neurasthenia/organic
11 Scand. J. Work were active among the eight. occupations. found. No the exposed subjects syndrome
& Environ Health workers at the statistically significant and an exposure-effect effects
(Supp.2, 1985) time of exam. differences was diffuse subjective
between found. Cerebellar symptoms without
subgroups, nor blood flow was reduced objective deficits
dose-response relationship by 4%. Neuropsychological in currently
found, tests showed indication exposed workers
with respect to of brain with a mean of 18
serum enzyme dysfunction in 14% years exposure.
tests. of the exposed Only objective
subjects in comparison neurobehavioral
to none in finding was decreased
the reference attention
group (increased in highexposure
power in the delta subgroup. Also
and beta bands). found changes in
The exposed subjects EEGs and lower
performed cerebellar blood
significantly worse flow (but not
on attention tests. pathologically
lower).
Questionnaire, regional Exposure index Neurological: A "The psychological No signs of clinical
cerebellar based on sum neurophysiological investigation disclosed PN were
blood flow tested, (HE) of the quotients exam of the very few found; in fact,
EEGs, PNS tests of concentration/ PNS showed no statistically significant with the except of
(NCVS, nerve potential TLV was difference between different between the response of
amplitude, used. Mean exposure the groups. the exposed the sural nerve,
vibration and was 16 Clinical chemistry and reference the exposed
temperature HE X years: median demonstrated groups..... The workers had better
thresholds), blood was 10HE X no differences main finding in our test results
tests, physical years. that could be explained study was the significant than the reference
and neurological by solvent differences group.
exam. exposure. in ... sustained
focused attention
...." Effect of exposure
seems to be
on attentive capability,
rather than
complex, symbolic
or intellectual operations.
Deficit
was present only
*210
in the high exposure
subgroup.
"A prolonged exposure
... seems
to cause a deficit
in sustained focused
attention.
The exposed subjects
were fulltime
workers and
were nonpatients
in the sense that
they had not
sought medical
care for suspected
disease or solvent
poisoning."
Life-style, medical, Two subjects in PNS: "The neurographic None of the workers
mental, and each group had and psychophysiological had conditions
sociological confounding clinical signs of variables tended to that had prompted
factors slight neuropathy. be slightly better them to seek
were included in Significantly among the exposed medical attention
the analysis. more exposed workers or which would
workers reported than among referents. affect daily life
mental exhaustion The only exception activities, i.e., the
during the work was the effects, if any,
day, but physical sensory response were subclinical
exhaustion was of the sural in magnitude.
rare in both nerve.... There
groups. Exposed was no significant
subjects complained difference between
of more the subgroup
CNS and PNS with low and high
symptoms (significant exposure indices."
differences: Authors conclude:
(CNS) fatigue, "Although the preliminary
memory failure, survey
irritability; indiated a slightly
(PNS) tingling, increased prevalence
paresthesia, of cases with
numbness; (psychosomatic) neurographic
headache, signs of polyneuropathy,
sweating, this increase
chest oppression)), was not
with trend confirmed in the
towards more quantitative evaluation
complaints in of the measurements.
high exposure
subgroup. Supports
finding of
neurasthenia.
Exams were performed EEGs: differences "However, the significantly,
on Monday. in power increased
within frequency temporal
bands, and different dispersion of the
relative distribution sensory action potential
of EEG in of the sural
the anteroposterior nerve is noteworthy
direction. and may indicate
Tentatively suggest a sign of mild
that changes affection of the
reflect a neurotoxic most peripheral
effect. sensory neurons
examined in this
study."
Regional cerebellar "In general we did
blood flow was not find impairment
4% lower (p better
nerve function parameters,
except
for the longest
sensory nerve fiber
of the body in
the sural nerve
...."
Psychiatric interview: Notes that literature
symptom describes the
score for exposed onset of PN as insidious.
group was significantly
higher for
every reported
symptom (inner
tension, mood lability,
worrying,
hostility, reduced
sexual interest,
bowel problems,
epigastric pain,
increased sleep,
headache, fatigability,
concentration,
learning.
*211
problems, short-term
memory
problems.) Supports
the presence
of neurasthenia/organic
affective syndrome.
(Though
in the majority of
cases, low scores
were reported for
both groups.)
Psychological: None of the subjects
battery of cognitive "had signs of
tasks. "Of any major disease
the 14 variables that could affect
analyzed only one the nervous system
measure showed or daily life
statistical significance" activity."
the Dots
test [a cancellation
test of the
Bourdon-Wiersma
type; measures
perceptual
speed and accuracy].
Dots was
also the only test
that showed any
significant difference
between low,
medium, and high
exposure subgroups
[potential
does-response relationship].
Clinical
evaluation of
individual psychometric
profiles:
29/50 of exposed
subjects showed
no sign of cognitive
dysfunction;
14/50 slight deviation
from norm;
7/50 pathologically
affected. In reference
group, 32/50
were normal; 18/50
had slight deviations
in one function,
but none had
deviations in two
or more functions.
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Eugene D. Means Uncontrolled 7 men aged 17 to The lacquer thinner Unspecified Physical exam established "It is our conclusion No. This was a
et al., Pathology case-series report. 22 who repeatedly contained 11 a picture that one or case of repeated,
of Lacquer Thinner inhaled same ingredients, including of predominantly more of the constituents intentional, direct
Induced Neuropathy, brand of lacquer xylene motor of the inhalation. Even
5 Annals thinner (habitual (43.6% by volume), neuropathy with lacquer thinner so, the resulting
Clin. & Lab. Med. "huffers"). toluene severe neurogenic was responsible PN was symmetrical,
240 (1976) (3.9%), and n-hexane muscular atrophy. for the peripheral and the authors
(0.5%). Effect was neuropathy. The declined to
rapidly progressive, responsible chemicals conclude which of
symmetrical have not yet constituent chemical
motor and sensory been identified. or combination
neuropathy. None of the constituents of chemicals
Motor nerve conduction ... except caused the neuropathy.
velocities for minute To the extent,
were markedly quantities of n-hexane, they hazard
slowed. Fascicular to our a guess, the authors
biopsy specimens knowledge have suggest 2-heptanone
of sural been reported to was
nerve showed a exert toxic effects the culprit, not
striking loss of on the peripheral xylene, despite
myelinated nerve nervous system, the fact that the
fibers. Autopsy although central thinner was 43.6%
material in one effects have been xylene by volume.
case revealed described. Similarities
central chroatolysis in structure
of anterior between 2-heptanone
hom cells in the (methyl
lumboscacral enlargement amyl ketone) and
and methyl n-butyl ketone,
axonal swellings a known
in the fasciculus cause of peripheral
gracilis. neuropathy, suggest
that 2-heptanone
alone or in
combination might
be the responsible
chemical."
Notes association
of PN with n-hex-
*212
ane and methyl n-butyl
ketone.
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Kaj Husman, Cross-sectional Subjects: 102 active Exposure to variety Exposure at 1/3 See next column. Symptoms of fatigue No. Describes
Symptoms of Car study with age-matched male car of solvents, TLV. Exposure and disturbances acute intoxicating
Painters with reference. painters from 27 including toluene, ranged from 1-40 in memory effects in currently
Long-Term Exposure Helsinki garages xylene (5.8 ppm), years (14.8 mean, and vigilance exposed painters
to a Mixture [the same group butyl acetate, SD 8.5). occurred significantly with a mean
of Organic as in Scppalainen white spirit, etc. more frequently of 14.8 years of
Solvents, 6 Scand. (1978) and Husman among exposure. No evidence
J. Work & Environ. (1980), supra]. exposed group. of PN
Health 19 When symptoms found.
(1980) during the work-shift
were compared,
irritation
and prenarcotic
symptoms (itching,
nausea,
drunken feeling,
dizziness, shortnes
of breath,
absentmindedness,
misunderstanding
orders) were reported
significantly
more frequently.
Symptom questionnaire. Reference group No difference in
consisting of railroad symptoms of PN
engineers (numbness or tingling
and assistants. in the legs).
Referents had
somewhat higher
education.
No statistically
significant trend
found between
high and low exposure
subjects on
general subjective
(chronic) symptoms.
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Stephanie S. Padilla Experimental animal Rats Xylene Exposed to varying See next column. Only relatively severe No. Animal study
& Donald P. study. concentrations concentrations involving >500
Lyerly, Effects of of p-xylene, (800 or ppm exposure.
p-Xylene Inhalation ranging from 50 1600ppm for 1.5 Only found that
on Axonal ppm for a single weeks) produced at 1600ppm effects
Transport in the 6-hour exposure significant reduction on axonal
Rat Retinal Ganglion to 1600 ppm, in axonal transport could
Cells, 101 6hr/day 5days/week, transport. Decrease last 13 days. Extrapolation
Toxicology & 1.5 weeks. in axonal from
App. Pharmacology transport after 13 13-day effect in
390 (1989) days after cessation rats to permanent
of exposure effect in humans
seen, but only in would be speculative.
the 1600 ppm rats.
Authors suggest
this may indicate
that p-xylene can
have permanent
effects; "once deficits
are manifest,
they can persist
even after exposure
has ceased."
Notes that "there
is sparse information
regarding the
toxicity of xylene
in humans or in
experimental animals."
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Herbert H. Review article on N/A n-hexane, acrylamide, N/A N/A Describes the axonal No. Discussion of
Schaumburg & the anatomy and methyl n-butyl "dying back" pathogenic effects
Peter S. Spencer, pathology of the ketone, and theory of pathogenesis. are expressly limited
The Neurology peripheral nerve 2,5-hexanedione Cites n-hexane, to 3 solvents
and Neuropathology acrylamide, other than xylene.
of the methyl n-butyl
Occupational ketone, and 2,5-hexanedione
Neuropathies, 18 as
J. Occupational known causes:
Med 739 (1976) "this discussion is
centered primarily
on these compounds."
Does
not discuss xylene.
*213
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Table 3. Literature Cited by Caravanos.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Supports Conclusion
that Subacute
Exposure
can Cause Chronic
Duration and/or Symptoms Described Authors' Comments CNS or PNS
Article Type Subjects Substance Dose or Tested and Conclusions Effects?
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
L. Atkinson et al., Uncontrolled case 65 year-old presented Paint contained, 1 hour Transient bone Authors attributed No. Reports only
Toxic Reaction to report to hospital 35.7% white spirit, marrow suppression the effects to the acute intoxicating
Inhaled Paint in acute confusional an aliphatic hydro-carbon, and evidence white spirit, but effects which resolved
Fumes, 65 Postgrad, state, following and of liver cell damage cautioned that the spontaneously
Med. J. 559 one hour 0.9% xylene. was observed, "full range of with no residua.
(1989) of exposure to but "[t]he patient symptoms cannot Note:
polyurethane improved spontaneously be explained on Caravanos specifically
paint fumes in over a 3 the basis of inhaling cited this
small, unventilated day period without paint fumes article as evidence
room. any specific alone." that acute
therapy." A follow-up exposure to xylene
examination at 500 ppm
one month later could cause the
showed the chronic PNS and
patient to be CNS effects alleged
healthy and to by Mr.
have normal liver Amorgianos.
and blood function. (Caravanos Dep.
at 163-64.)
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
M.A. Bakinson & Summary of case Not specified Xylene Not specified See next column. 38 cases of solvent No. No chronic
R.D. Jones, Gassings reports poisoning attributed effects were reported,
Due to Methylene to xylene, including and no
Chloride, one death. concentrations or
Xylene, Toluene, The cases showed durations were
and Styrene Reported symptoms consistent specified.
to Her with acute intoxication,
Majesty's Factory and the
Inspectorate one death was attributed
1961-80, 42 Brit. to acute
Med. J. 184 (1985) narcosis resulting
in respiratory depression.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
B.A. Olson, Effects Cross-sectional 47 current workers Primarily xylene Exposure in excess See next column. Exposed workers No. Finds symptoms
of Behavioral study with reference with occupational and toluene of TLVs for performed less consistent
Performance of group. exposure to more than 10 well on battery with acute intoxication
Workers in the organic solvents years tests than control in currently
Paint Industry, 4 group and reported exposed workers
Neurobehavioral a higher number with more
Toxicology & Teratology of neurasthenic than 10 years of
703 (1980) symptoms on chronic exposure.
their questionnaires. No conclusion as
to permanence of
the effects.
Administered
tests of simple reaction
time, perceptual
speed,
short-term memory,
and "critical
flicker fusion" before
and after a
workday.
Subjects also answered
questionnaire
regarding
subjective symptoms.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
R. Morley et al., See Table 2, supra.
Xylene Poisoning:
A Report on
One Fatal Case
and Two Cases of
Recovery After
Prolonged Unconsciousness,
3
Brit. Med. J. 442
(1970)
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Div. of Safety Research, Uncontrolled case 34 year-old male Xylene Not specified Painter lost consciousness N/A No. Since the
U.S. Dep't report. painter due to worker died immediately
of Health & Human breathing xylene because
Servs., fumes and fell off of the 140-foot
Painter Dies in a a 140-foot water fall, no conclusion
140-Foot Fall at tower. can be drawn as
*214
a Municipal Water to what the long-term
Tower, September effects of
22, 1988. the exposure on
Report No. the painter would
FACE-89-5 have been.
(1989)
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
S.D. McQuilkin, Report of government N/A See next column. See next column. Concentrations of The author concluded No. The report
Div. Of Surveillance, inspection benzene, chromium, that the excess concludes with
Hazards of painting and coaltar-pitchvolatile, concentrations recommendations
Evaluation & curing operations and hexamethylene-diisocyanate of former for better industrial
Tech. Assistance at the titled work were group of chemicals hygiene measures,
Branch, NIOSH, site. found to exceed posed a serious but provides
U.S. Dep't of OSHA standards, health hazard to no evidence
Health, Educ. & while the concentrations workers, but the on the health effects,
Welfare, Health of xylene evaluation did not acute or
Hazard Evaluation and other solvents report any illnesses. chronic, of xylene
Report, were found or any other solvent.
Continental Columbus to be within
Corp., OSHA limits.
Columbus, WI,
Report No.
HHE-78-102-677
(1980)
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
ACGIH, Documentation Summary of evidence N/A Xylene N/A N/A The ACGIH documentation No. No information
of the supporting reports is given on
Threshold Limit AGCIH's TLV for animal studies on the long-term effects
Values and Biological xylene the lethal dose and of either
Exposure concentration of acute or chronic
Indices 1732-38 xylene, eye irritation, xylene exposure
(ed. and date unknown) and carcinogenic on human CNS or
(chapter and mutagenic PNS function.
on xylene). effects. The Nor, assuming
only reference to that one can reliably
neurological effects extrapolate
comes in the from effects on
report of a study rats or rabbits to
in which nine rats effects on humans,
inhaled 690 ppm of see Joiner,
mixed xylene, 522 U.S. at 144,
eight hours a day, 118 S. Ct. at 518,
six days a week, does the one
for 110 to 130 days study of rats and
and six rabbits inhaled rabbits exposed
1200 ppm of to 690 and 1200
xylene for eight ppm xylene, respectively,
hours a day, six support
days a week, for Caravanos's
forty to fifty days. conclusion that a
That study reported single day of exposure
that "some" of (or even
the animals suffered Dr. Rutchik's estimate
paralysis of of four
the hind legs. straight days with
intermittent days
of exposure over
the preceding
month, averaging
three to five
hours on each
such day) at 500
to 2,000 ppm of
xylene can cause
permanent CNS
or PNS damage
in humans, since
that study involved
exposures
that lasted for a
much longer and
more continuous
period, viz., eight
hours a day, six
days a week for
110 to 130, or forty
to fifty days,
respectively.
Two other animal
studies cited in the
ACGIH documentation
that involved
exposures
of similar concentrations
and durations
reported no
significant pathological
results: in
one such study,
rats, guinea pigs,
monkeys, and dogs
were continuously
exposed to o-xy-
*215
lene at 780 ppm
for six weeks, or
78 ppm continuously
for 90 days;
in the other such
study, rats and
dogs were exposed
to 810 ppm of
mixed xylene for
13 weeks.
The human studies
reported only include
results on
eye irritation and
acute intoxicating
effects.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Table 4. Time records and daily reports.
Romano-Ahearn &
Triventure Time Dynamic Inspectors KTA-Tator Daily Painting
Date Records[*] Daily Log[**] Inspection Report[***]
------------------------------------------------------------------------------------------------------------------
Number of Comments Regarding Comments Regarding Coating(s) Applied and
Hours Mr. Amorgianos Day's Activities Method(s) of Application
Worked
"AS" = airless sprayer
"B" = brush
"B & R" = brush and roller
7/22/95 7 - No coating
7/23/95 7 - No coating
7/24/95 8 - No coating
7/25/95 8 - Zinc Plate 49 with AS from 10am to 1pm
7/26/95 8 - No coating
7/27/95 0 - No coating
7/28/95 0 - No coating
7/29/95 7 Blasting & Painting Zinc Plate 49 with B; Epolon Mastic with AS & B
from 11am to 2pm
7/30/95 7 Painting Epolon Mastic with AS & B until 1:30pm
7/31/95 8 [Not specified] Epolon Mastic with B & R; Zinc Plate 49 with
AS & B from 1pm to 3:15pm
8/1/95 8 - Epolon Mastic with B & R
8/2/95 8 [Not specified] Epolon Mastic with B & R; Acrolon with B & R;
Zinc Plate 49 with AS from 11am to 1pm
8/3/95 0 - No coating
8/4/95 0 - No coating
8/5/95 7 - Epolon Mastic with B & R
8/6/95 0 - No coating
8/7/95 7 - Urethane with B & R
8/8/95 7 Everyone painting Urethane with B & R
red
8/9/95 8 Painting Cool red urethane with AS
8/10/95 0 No work No coating
8/11/95 0 - Acrolon II cool red with B & R
8/12/95 7 - Antigraffiti coat with B & R
8/13/95 7 [Not specified] No coating
8/14/95 3 - No coating
8/15/95 8 Mostly blasting No coating
8/16/95 8 Blasting and No coating
cleaning
8/17/95 7 Blasting and -
cleaning
8/18/95 7 Zinc primer Zinc Plate 49 & Reducer 145 with AS
8/19/95 7 Priming Zinc Plate 49 & Reducer 145 with AS
8/20/95 7 Prime Zinc Plate 49 & Reducer 145 with AS until 2pm
8/21/95 8 Touch up Zinc Plate 49 with B & R; Epolon Mastic with
AS; Red oxide with AS[illegible]
*216
8/22/95 8 Mastic Epolon Mastic with AS; Red oxide with AS
[illegible]
8/23/95 8 - No coating
8/24/95 8 Just blasting No coating
8/25/95 8 - Zinc Plate 49 with AS
8/26/95 7 2 men spraying Zinc Plate with AS; Epolon Mastic 81 with AS
used about 100
gals of Mystic
8/27/95 5[*] Cleaning + doing Epolon Mastic 81 with AS; No coating
holidays only 3
men showed up
8/28/95 8 Touch up + Zinc Plate 49 with AS; Epolon Mastic 81
primed with AS
NOTES
[1] Plaintiffs do not claim that Mr. Amorgianos's alleged injuries were due to exposure (excessive or otherwise) to lead paint dust.
[2] Mrs. Amorgianos testified that when she picked Mr. Amorgianos up on his last day of work, he did not bring his painter's uniform or any of his painting equipment with him, though he was carrying a black bag. (Tr. 6/17/98, at 138.) Further, one of Mr. Amorgianos's co-workers who testified for plaintiffs, Nikos Kpitikos, testified the workers on the Project did not take their respirators home with them but rather left them at the work-site. (Tr. 6/23/98, at 26.)
[3] Tyvek is a synthetic, paper-like fabric used, inter alia, for making protective apparel. See (visited February 8, 2001).
[4] Mr. Amorgianos, however, denied making such a statement. (Id.)
[5] In colloquy outside the presence of the jury, it was indicated that the IME company had been retained by the worker's compensation carrier that covered Mr. Amorgianos's employer. Dr. Rubin testified to the jury that he was unaware who had contracted for the IME. (Tr. 6/22/98, at 14-15.)
[6] The PEL is the time-waited average concentration to which a worker can be safely exposed over the course of an eight-hour work-day. See 29 C.F.R. § 1900.1000 tbl. Z-1 n. 1. OSHA promulgates PELs for hundreds of workplace chemicals. See id. tbl. Z-1.
[7] Plaintiffs' experts' opinions on questions (1), (2), and (5) appear to be reliable under Daubert.
As to question (2), although, in granting a new trial, the trial court could properly take exception to the fact that Dr. Moline, in forming her diagnosis, relied on the interpretation of Mr. Amorgianos's EMGs and nerve conduction studies by neurologists who did not testify at trial, her testimony, nevertheless, was admissible and was admitted. As detailed above, Background (3) (B), the dispute at trial centered instead on the non-expert issue of whether Mr. Amorgianos was in fact provided with such equipment.
As to question (2), although in granting a new trial, the trial court could properly take exception to fact that Dr. Moline, in forming her diagnosis, relied on the interpretation of Mr. Amorgianos's EMGs and nerve conduction studies by neurologists who did not testify at trial, her testimony nevertheless, was admissible and was admitted. See Fed. R.Evid. 703 ("The facts or data in the particular case upon which an expert bases an opinion or inference may be those perceived by or made known to the expert at or before the hearing. If of a type reasonably relied upon by experts in the particular field in forming opinions or inferences on the subject, the facts or data need not be admissible in evidence in order for the opinion or inference to be admitted."); id. advisory committee's note (observing that "a physician in h[er] own practice bases h[er] diagnosis on information from numerous sources ..., including ... reports and opinions from nurses, technicians and other doctors" and concluding such basis "ought to suffice for judicial purposes").
Finally, as to question (5), Dr. Moline's opinion on specific causation was, as she testified at trial, based on (1) explicit consideration of a number of other known and suspected causes of peripheral neuropathy, (2) the elimination of those other possible causes through a variety of diagnostic tests, and (3) the temporal proximity of Mr. Amorgianos's alleged exposure and the onset of his alleged symptoms. As such, Dr. Moline's opinion on specific causation appears to be based on reliable methodology and a reliable application of that methodology and is admissible to the extent that the plaintiffs are able to produce admissible expert evidence as to question (4).
[8] While this motion was pending, a proposal to amend Rule 702 to read as quoted above became effective. As the Advisory Committee Note to the 2000 Amendments makes clear, the amendment was not intended to effect a departure from Daubert or its progeny. See Fed.R.Evid. 702 adv. committee note (2000 Amendments) (endorsing the Daubert gatekeeping framework and extensively discussing post-Daubert decisions with approval). Consequently, post-Daubert, pre-amendment case law construing Rule 702 remains fully applicable to this motion and will be relied upon throughout this opinion.
[9] Compare Washburn v. Merck & Co., 213 F.3d 627, 2000 WL 528649 (2d Cir.2000) (Table) (holding that district court did not abuse its discretion under Daubert, where district court excluded experts on basis of a critical analysis of studies on which they relied), with In re Joint E. & S. Dist. Asbestos Litig., 52 F.3d 1124, 1126, 1133, 1139 (2d Cir.1995) (reviewing grant of judgment as matter of law, but in process suggesting that Daubert does not permit district court to analyze studies upon which expert relies in determining admissibility; "the district court's analysis ... was rife with independent assessments of witnesses' conclusions ..., often in a manner that appears to us to stretch ... Daubert beyond [its] limit"), and Zuchowicz v. United States, 140 F.3d 381, 387 (2d Cir.1998) (stating that lack of textual authority for expert's opinion goes to weight, not admissibility).
[10] Justice Stevens was alone among the justices in concluding that the Joiner district court had impermissibly assessed "the validity or strength of an expert's conclusions, which is a matter for the jury." Joiner, 522 U.S. at 154, 118 S. Ct. at 523 (Stevens, J., concurring in part and dissenting in part).
[11] Although Maiorana actually involved a determination of the sufficiency of expert opinion evidence already held admissible, the Second Circuit repeatedly stated that the type of inquiry engaged in by the district court in that case was beyond the limits of what Daubert would permit even on a preliminary assessment of admissibility. See Maiorana, 52 F.3d at 1133, 1137, 1139.
[12] The literature cited by plaintiffs' experts also includes several review articles that summarize the results of existing studies and one experimental study on rats. See infra Appendix tbls. 1-3.
[13] As noted in the Agency for Toxic Substances and Disease Registry's toxicological profile on xylene:
Laboratory tests can detect xylene or its breakdown products in exhaled air, blood, or urine.... However, a urine sample must be provided very soon after exposure ends because xylene quickly leaves the body. These tests are not routinely available at your doctor's office.
Agency for Toxic Substances & Disease Registry, U.S. Dep't of Health & Human Servs., Toxicological Profile for Xylenes (Update) (1995).
[14] Certain overtones in defendant's argument appear to suggest that the failure to take into account an individual's rate of absorption of a particular chemical is also a defect in an opinion on specific causation. The suggestion is that, for all plaintiffs' experts know, Mr. Amorgianos may be a rare individual whose bodily defense mechanisms render him impervious to xylene. (See, e.g., Def.'s Letter Br. at 5 (quoting Rutchik Dep. at 336 ("Q. Of the range, the 500 parts per million to 2,000 parts per million of xylene that you have indicated is your opinion regarding exposure, would you agree that, based on the body's defense mechanisms, that the amount of xylene, if any, absorbed by Mr. Amorgianos was not that range ...?" (emphasis added))).) Defendant has not expressly moved to exclude plaintiffs' experts' opinions on specific causation, but if they had, plaintiffs' experts' failure to exclude the possibility that Mr. Amorgianos has such unusual physiological characteristics would not be a ground for finding their opinion on specific causation unreliable. Cf. Zuchowicz, 140 F.3d at 390 (holding that plaintiff need not exclude every other possible cause of illness). Such speculative considerations defendant has not conducted any tests on Mr. Amorgianos that would support the possibility, nor has it presented any evidence on the percentage of individuals who are resistant in such a manner to xylene go to the weight of the opinion, not its admissibility. Consequently, the proper place for exploration of the possibility that Mr. Amorgianos has such a resistance to absorption of xylene would, instead, be on cross-examination or in any rebuttal opinion on specific causation that defendant wished to offer.
[15] Although Dr. Rutchik's expert report includes certain estimates of the xylene concentration within the containment, Dr. Rutchik cites Caravanos for the underlying calculations. (Def.'s Letter Brief of 12/6/99, Ex. D, at 12.) In his deposition, Dr. Rutchik stated that he was not qualified to estimate the xylene concentration within the containment and that, in reciting estimates of concentration in his report, he was relying entirely on Caravanos's calculations and expertise. (See Rutchik Dep. at 302 ("It is not my expertise to do exposure calculations, nor do I have the ability to know the details of Dr. Caravanos' methods."); id. at 324-25 ("Q. Would it be fair to say ... that the exposure or dose information, relative to xylene, that is contained in your report, in part per million form, is exclusively the work of Dr. Caravanos? A. Correct."); see also id. at 302-325.) Accordingly, to the extent that plaintiffs are preferring Dr. Rutchik as an expert on xylene concentration, Dr. Rutchik's testimony on that issue is excluded.
Of course, if plaintiffs produce admissible evidence that the xylene concentration was in the amounts assumed in Dr. Rutchik's report, Dr. Rutchik may testify as to the health effects of exposure to such concentration, provided his testimony is otherwise reliable. As discussed below, it is not. See infra Discussion (3) (E).
[16] Data on these additional variables was available to Caravanos. As he noted in his deposition, the temperature, dew point, and humidity were recorded each day in the KTA-Tator logs. (Caravanos Dep. at 80.) When asked on cross-examination at trial why he did not include the additional variables he cited as part of a "proper exposure assessment" in his calculation, Caravanos testified, "I I did not find it necessary," adding, cryptically, "It was summer time, so I assumed the volatilization rate was going to be established." (Tr. 6/18/98, at 75.)
[17] To introduce a term that will sometimes be used below, such duration falls into the category toxicologists label as "subacute." See Casarett & Doull's, supra, at 15 (explaining that "acute exposure" refers to "continuous exposure for less than 24h;" "subacute exposure," to "repeated exposure to a chemical for 1 month or less;" "subchronic," to repeated exposure for one to three months; and "chronic exposure," to repeated exposure for more than three months).
[18] "Lipophilic" means "capable of dissolving, of being dissolved in, or of absorbing lipids." Stedman's Medical Dictionary 886 (25th ed., 1990). Lipids, in turn, are "[a]ny of a large class of organic substances, insoluble in water and typically greasy to the touch, including the fats, waxes, and sterols." Funk & Wagnalls Encyclopedic College Dictionary 788 (1968).
[19] Xylene is also known as xylol, zylol, and dimethylbenzene.
[20] Indeed, the acute intoxicating effects of xylene and other organic solvents will be familiar to anyone who has felt light-headed as a result of breathing fumes from paint thinner. As documented in an article cited by Dr. Rutchik, these effects are sufficiently well-known to the general public that it is not uncommon for individuals to inhale intentionally vapors from paint thinners or model glues that contain xylene or other organic solvents, such as toluene, in order to "get high." See Eugene D. Means et al., Pathology of Lacquer Thinner Induced Neuropathy, 5 Annals Clin. & Lab. Med. 240 (1976) (cited by Dr. Rutchik).
[21] The parties presumably ignored this question because those acute conditions could not have accounted for any more than a tiny fraction of Mr. Amorgianos's damages in and of themselves.
[22] This ruling is subject to the requirement that plaintiffs' introduce admissible expert evidence that the concentration of xylene within the containment was in excess of the OSHA PEL for xylene (100 ppm). If plaintiffs do not produce such evidence, then their experts' opinion on the acute aspect of Mr. Amorgianos's alleged illness will be excluded as well, for, as Caravanos testified, a person "could work at 100 part per million [of xylene] all day long most of the time and not suffer any health effects." (Tr. 6/18/98, at 40-41.)
[23] By way of comparison, one of the articles cited by Dr. Moline states that glue-sniffing results in exposures of 50 to 100 times the PEL. See Anna Marie Seppalainen, Neuropsychological Effects of Long-Term Exposure to a Mixture of Organic Solvents, 4 Scand. J. Work Environ. & Health 304, 305 (1978). For xylene, this means an exposure of 5,000 to 10,000 ppm, a concentration far in excess of Caravanos's current upper estimate of 2,000 ppm exposure on Mr. Amorgianos's part.
[24] The pathogenesis of n-hexane and Mn BK-induced PN is well-understood. See Casarett & Doull's, supra, at 471. As explained in a toxicology text cited by Dr. Rutchik as authoritative, n-hexane and Mn BK are both metabolized by the human body into 2,5 hexanedione. See id. at 471. That common metabolite in turn is the actual disease-causing agent. See id. 2,5 hexanedione reacts with the proteins that make up the cytoskeleton of axons, causing them to break in two. See id. at 470-71. Such breakage in the long axons that lead to the extremities results in the loss of sensation in and motor control of the extremities that characterizes PN. See id.; see also Rom, supra, at 701, 1095 (cited by Dr. Rutchik as authoritative) (same).
Interestingly, xylene is not metabolized by the body into 2,5 hexanedione, see Hazardous Materials Toxicology 1093 (John B. Sullivan, Jr. & Gary R. Krieger eds., 1992) (cited by Dr. Rutchik as authoritative) (noting that xylene is metabolized and excreted as methyl hippuric acid), and Dr. Moline candidly admitted at trial that she knew no biological explanation as to how xylene could cause the kind of axonopathy that underlies PN, (Tr. 6/18/98, at 133). Thus, to the extent Dr. Moline's opinion on general causation is based on the inference that n-hexane, Mn BK and xylene are all organic solvents; n-hexane and MnBK are known to cause PN; therefore, xylene can also cause PN, her opinion is not supported by the cited literature. Cf. White & Proctor, supra, at 1239 (noting that the "toxicity of individual solvents to human beings depends on the mechanism of action (which is usually related to their structure) and the amount or dose of exposure" (emphasis added)).
[25] For a discussion of Linz et al. (1986), see the preceding analysis of Dr. Moline's opinion, supra Discussion (3) (D).
[26] The AGCIH publishes its own recommendations for the maximum exposure limits for various industrial chemicals, using the term "threshold limit value." Like OSHA's PELs, AGCIH TLVs are recommended maximum time-weighted average exposure limits over the course of an eight-hour workday. The AGCIH TLV for xylene is the same as OSHA's PEL for xylene, viz., 100 ppm.
[27] See supra note 22 and accompanying text.
[*] Def.'s Letter Brief of 12/6/99, Ex. K.
[**] Id., Ex. L. "-" signifies that no report was filed on that date.
[***] Id., Ex. J.
[*] Per Mr. Amorgianos's trial testimony. (Tr. 6/17/98, at 88.)
Some case metadata and case summaries were written with the help of AI, which can produce inaccuracies. You should read the full case before relying on it for legal research purposes.
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
