filed: September 20, 1990; As Corrected October 31, 1990. As Corrected November 13, 1990. As Amended October 29, 1990. As Corrected November 23, 1990. As Corrected January 4, 1991.
On Appeal From the United States District Court for the Eastern District of Pennsylvania; D.C. Civil Nos. 86-7414, 86-7415, 86-7416, 86-7417, 86-7418, 86-7419, 86-7420, 86-7421, 86-7422, 87-5304, 86-2229, 87-1258, 87-1190, 87-0712, 86-7561, 87-5269, 86-2235, 86-2669, 86-5277, 87-3227, 87-2874.
Becker, Mansmann and Nygaard, Circuit Judges.
This is a toxic tort case brought by some thirty-eight persons who have either worked in or lived adjacent to the Paoli railyard, an electric railcar maintenance facility at the western terminus of the noted Paoli Local, which serves the Philadelphia Main Line. The plaintiffs' primary claim is that they have contracted a variety of illnesses as the result of exposure to polychlorinated biphenyls, better known as PCBs. PCBs are toxic substances which, as the result of decades of PCB use in the Paoli railcar transformers, can be found in extremely high concentration at the railyard and in the ambient air and soil. The defendants are Monsanto Corporation, the nation's leading manufacturer of PCBs (marketed under the trade name "Aroclor"); General Electric Company, manufacturer of the transformers; Amtrak, owner of the railyard site since 1976; Conrail, which operated the facility between 1976 and 1983; the Southeastern Pennsylvania Transit Authority (SEPTA), which has operated the facility since 1983; and the City of Philadelphia, which owns some of the railroad cars at the facility.*fn1
This opinion addresses an appeal by all plaintiffs from the grant of summary judgment by the district court in favor of all defendants on all claims except those for property damage and response costs under CERCLA.*fn2 We direct our attention principally to a series of pretrial evidentiary rulings by which the district court apparently excluded*fn3 the bulk of the expert reports and testimony upon which plaintiffs relied to establish (1) that they were subject to an abnormally high level of PCB exposure, and (2) that this exposure caused them harm. Because the grant of summary judgment inexorably flowed from these evidentiary rulings, if they are set aside, so must be the summary judgment. Our scrutiny of the rulings will focus not only upon their legal foundations, but also on the procedures by which they were made and the adequacy of their articulation.
We conclude that the district court's evidentiary rulings must be set aside for a number of reasons. One problem with the district court's rulings is procedural. The court not only failed to give plaintiffs an adequate opportunity to present their factual and legal contentions on evidentiary issues, but it also ruled on an inadequate factual record and it failed adequately to articulate the bases for its rulings. It also failed to follow the protocols established by the jurisprudence of this court for evidentiary rulings governed by Fed. R. Evid. 702 and 703.
Other problems with the district court opinion are substantive. The court applied too stringent a standard to the qualification of experts under Rule 702. The court also erred in its application of the Downing test for the admissibility of novel scientific evidence (under Rule 702). Given these improper evidentiary exclusions, we cannot affirm the district court's summary judgment ruling. If the improperly excluded evidence is considered, the record contains genuine issues of material fact on the toxic tort issues.
A number of other discrete legal issues are also before us on appeal. These include the viability of plaintiffs' claims to recover the costs of periodic medical examinations necessary to protect against the development of latent diseases caused by their exposure to PCBs ("medical monitoring") under Pennsylvania law; the propriety of the district court's refusal to permit certain plaintiffs voluntarily to dismiss their complaint so as to proceed at a later time when their apparently sub-clinical injuries manifest themselves; and the availability to SEPTA of a lack of notice defense under 42 Pa. Cons. Stat. Ann. § 5522. We find that the district court abused its discretion in refusing to permit the voluntary dismissal without prejudice of certain plaintiffs' claims, and that the court erred as a matter of law in its analysis of both the medical monitoring and SEPTA notice issues. For all these reasons, we must reverse the grant of summary judgment and remand for further proceedings.
Plaintiffs filed their complaints in the district court for the Eastern District of Pennsylvania beginning in April 1986. The complaints alleged a variety of theories of recovery, including claims based upon CERCLA, common law tort, and the medical monitoring doctrine. The twenty-one actions before us on this appeal were consolidated. On September 24, 1987, in response to a motion by defendants, the district court filed a case management order which provided a schedule for conducting further discovery and filing summary judgment motions.*fn4
The defendants filed a joint motion for summary judgment.*fn5 After plaintiffs answered the motion, attorneys on both sides requested oral argument. In a letter dated October 28, 1988, the court denied these requests, stating that oral argument would be unnecessary "because the issues contained in those motions have been thoroughly and extensively briefed and because I have been working with this case for over a year . . . ." The court also failed to conduct in limine hearings regarding the admissibility of the plaintiffs' expert testimony, notwithstanding defendants' summary judgment strategy that depended largely on exclusion of that testimony under Fed. R. Evid. 702, 703 and 403.
On November 28, 1988, the district court granted defendants' joint motion for summary judgment against all plaintiffs on the personal injury claims. The court's order was accompanied by an opinion, discussed below in Part IV, concentrating on the exclusion of plaintiffs' expert testimony. These appeals followed.
II. APPELLATE JURISDICTION
Defendants make a number of attacks upon our appellate jurisdiction, all of which we find without merit, and only one of which warrants extended discussion: did the original notice of appeal in ten of the cases fail to identify the appealing parties with the specificity required by Torres v. Oakland Scavenger Co., 487 U.S. 312, 101 L. Ed. 2d 285, 108 S. Ct. 2405 (1988)?*fn6 In Torres, the notice of appeal was captioned, "Joaquin Moreles Bonilla, et al., Plaintiffs in intervention." The body of the notice named fifteen of the sixteen putative appellants, but not Torres. The Court concluded that the notice was insufficient to specify Torres as an appellant, and that he was therefore barred from pursuing his appeal for failing to comply with the requirements of Fed. R. App. P. 3(c). See 487 U.S. at 317-18.
We recently had the opportunity to construe Torres in Dura Systems, Inc. v. Rothbury Investments, Ltd., 886 F.2d 551 (3d Cir. 1989), cert. denied, 493 U.S. 1046, 107 L. Ed. 2d 838, 110 S. Ct. 844 (1990), in which we held that a consent order, entered after a notice of appeal but within the period required for timely notice of appeal, could confer jurisdiction over parties not explicitly named in the notice of appeal. See id. at 555. We summarized the applicable principles as follows:
In formulating its holding, the [Torres] Court made clear that Rules 3 and 4 of the Federal Rules of Appellate Procedure create a jurisdictional threshold, and that the requirements of the two rules may not be abrogated for "good cause shown" under Fed. R. App. P. 2. Moreover, the fact that Rule 3 excuses "informality of form or title" in a notice of appeal does not forgive compliance with the Rule's requirements: "permitting imperfect but substantial compliance with a technical requirement is not the same as waiving the requirement altogether as a jurisdictional threshold." Although the Torres court mandated compliance with the specificity requirement of Fed. R. App. P. 3(c), it recognized that:
the requirements of the rules of procedure should be liberally construed and that 'mere technicalities' should not stand in the way of consideration of a case on the merits. Thus, if a litigant files papers in a fashion that is technically at variance with the letter of a procedural rule, a court may nonetheless find that the litigant has complied with the rule if the litigant's action is the functional equivalent of what the rule requires.
This approach mirrors the practice sanctioned in the Advisory Committee Notes to the 1979 amendment to Fed. R. App. P. 3(c), which cites with approval cases holding that, "so long as the function of notice is met by the filing of a paper indicating an intention to appeal, the substance of the rule has been complied with."
Id. at 554-55 (footnote and citations omitted).
Applying those principles here, it is not clear that plaintiffs' notice of appeal in the ten referenced cases, in its original form, was insufficient. For example, the original notice appears to have served as a "functional equivalent" of the requirements of Rule 3(c) because it mentions the docket numbers and surnames of the cases then before the district court. Indeed, correspondence from defense counsel confirms that no party was misled by the notice, and that all parties presumed it to include all plaintiffs referenced under the relevant docket numbers.
At all events, any impediment that might have existed was removed by a January 6, 1989, letter, just two days after the Rule 54(b) certification, from counsel for the subject plaintiffs to the clerk of this court, with copies to all counsel, identifying in detail the parties to the appeal. The letter is analogous to the consent order in Dura Systems in that the letter was filed within the period allowed for appeal. The "Court's directive to construe the rule 'liberally,' and to avoid a construction that would allow 'mere technicalities' to bar consideration of a case on the merits." Id. (quoting Torres, 108 S. Ct. at 2408) compels this result.*fn7 Accord Masquerade Novelty, Inc. v. Unique Industries, Inc., 912 F.2d 663 (3d Cir. 1990) (attorney appearance form and civil appeal information statement filed within time limit constitute adequate notice).
III. THE SUMMARY JUDGMENT RECORD
A. The Plaintiffs' Submissions
Plaintiffs set out to prove that their personal injuries were proximately caused by their exposure to the PCBs that defendants permitted to contaminate the area surrounding the Paoli Railyard. Their case depends upon expert testimony pertaining to exposure and causation. The attorneys for different plaintiffs employed different expert witnesses, and it is therefore convenient, in discussing the record before us, to categorize plaintiffs according to which counsel represents them.
Of the ten cases in which plaintiffs are represented by Kohn, Savett, Klein & Graf, P.C., or Klehr, Harrison, Harvey, Branzburg, Ellers & Weir, (the "Kohn/Klehr plaintiffs"), nine answered discovery with the opinions of three experts: Dr. Herbert Allen, Dr. Deborah Barsotti, and Dr. Arthur Zahalsky. In the tenth Kohn/Klehr case, Cunningham, and in the Reid case,*fn8 Dr. Harry Shubin submitted an opinion on the question of causation. In the nine cases in which plaintiffs are represented by D. Bruce Hanes, expert testimony was offered solely by Dr. G. John DiGregorio. The remaining plaintiffs offered no expert testimony.
Dr. Herbert Allen received his doctorate in environmental chemistry from the University of Michigan in 1974. He is currently employed as a professor of chemistry at Drexel University, where he serves as the director of Drexel's Environmental Studies Institute. Allen has published numerous scholarly articles. His primary role was to testify to the Kohn/Klehr plaintiffs' exposure to the Paoli Railyard's elevated PCB levels.
Initially, Allen noted the "extremely high levels" of PCBs in soil samples taken from the neighborhood adjacent to the yard. He explained that runoff from the railyard caused contamination in the soil on Central Avenue, with the highest concentrations of PCBs being found in residential yards adjacent to the railyard. Central Avenue samples contained concentrations as high as 577 mg/kg, while some residential yard concentrations were as high as 1000 mg/kg. Dr. Allen opined that the high concentrations of PCBs found deep in the soil indicated a discharge of extremely high amounts of PCBs. He also noted specifically that certain "heat-producing" operations, such as the welding and cutting of contaminated equipment and the burning of contaminated railroad ties, which employees testified had occurred at the yard, could have converted PCBs into other toxins such as PCDD's (dioxins) and PCDF's (furans). This testimony is particularly significant in view of the conclusion of certain of plaintiffs' proffered studies that exposure to PCDFs can cause numerous adverse health effects, see infra [Slip Op.] at 41-42.
Relying on his knowledge of the scientific literature, his own testing, the testimony of employees, and a scientific formula which he had devised, Dr. Allen calculated the amount of PCBs in plaintiffs' bodies based on the amount of PCBs in the soil. Among other things, he relied on the affidavit of an employee named Kraljevich who stated that the use of heat-producing tools caused PCBs to "hang in the air like a fog," and that leaking transformers caused foul PCB odors to permeate the air. Allen then concluded that neighborhood residents had been exposed to elevated PCB concentrations since approximately 1940. Although unable to quantify the extent of plaintiffs' exposure, Allen opined that the residential plaintiffs may have been exposed to air containing more than 10 g/m3 of PCBs, while railyard employees may have suffered even greater exposure.
Deborah A. Barsotti, Ph.D., offered expert opinions on both exposure and causation for the Kohn/Klehr plaintiffs. Dr. Barsotti, a toxicologist, received her doctorate in pathology from the University of Wisconsin Medical School in 1980, and is qualified to interpret human clinical tests. She has published a number of articles on the toxicity of PCBs, and her work has been cited in the Congressional Record and in legislative debates on the Toxic Substances Control Act. She is currently employed as the Chief of the Research Analysis Branch of the Agency for Toxic Substance and Disease Registry (ATSDR) of the United States Government.
Barsotti based her opinions regarding exposure on her review of the relevant scientific literature and on her own gas chromatography testing. She explained that PCBs may be absorbed into the body by oral ingestion, through the skin, or by inhalation, and that PCBs are transported through the body in blood, and eventually redistributed to fat and organs containing fat. She concluded that the plaintiffs had in fact ingested PCBs. A major part of Dr. Barsotti's exposure testimony consisted of her attempt to show, through gas chromatography tracing, that the PCBs to which plaintiffs were exposed came specifically from the Paoli Railyard. She did this by comparing chromatographic tracings of plaintiffs' blood to similar tracings from soil at Paoli. She then attempted to match certain "early emerging peaks," (in plaintiffs' blood tests which she testified related) to particular PCB isomers.
Barsotti used the results of these tests, along with medical and clinical records from the plaintiffs, to buttress her testimony regarding causation. In determining causation, she also personally inspected the railyard, and reviewed, inter alia, the Kraljevich affidavit, published reports and studies, and soil samples taken from the yard. She concluded that plaintiffs' exposure to PCBs at Paoli was a substantial factor in causing their particular injuries, including elevations in triglyceride, cholesterol, and liver enzyme levels.
Also testifying with respect to causation for the Kohn/Klehr plaintiffs was Arthur C. Zahalsky, Ph.D., who received his doctorate in microbiology from New York University in 1967. Dr. Zahalsky is a professor at Southern Illinois University, where he teaches courses in immunology and human diseases. However, he has spent the majority of his time in the past few years in his consulting business, which specializes in providing scientific consultation for litigation.
Dr. Zahalsky offered his opinion that plaintiffs have suffered immune system injuries as a result of their exposure to PCBs at Paoli. He testified that as a general proposition, PCBs damage the immune systems of humans and animals because they alter the cell production and replenishment rate of immune cells, and impair the survivability of those cells. Basing his opinion on a personal inspection of the railyard and surrounding area, a review of plaintiffs' medical records and PCB exposure history, and various laboratory test results and published reports, Dr. Zahalsky concluded that plaintiffs have sustained immune system damage, and that exposure to PCBs at Paoli was a substantial factor in causing such damage. Zahalsky submitted a list of 82 studies upon which he relied in formulating his opinion. A number of these studies discussed two notorious incidents of human beings ingesting contaminated rice oil. These incidents, which took place in Japan in 1968 and Taiwan in 1979, are referred to as the "Yusho" and "Yu Cheng" incidents. The oil was tainted with large quantities of Kaneclor, a Japanese analog of Aroclor that contains significant amounts of PCDFs, as well as PCBs.
Harry Shubin, M.D., an internist, offered opinions on the issue of causation in the Cunningham and Reid cases. In formulating his opinion, Dr. Shubin examined the plaintiffs and reviewed medical records and lab test results. He cited numerous published studies and reports on which he claims to have relied. Shubin was also informed that the EPA had removed PCB-contaminated soil from the Cunninghams' residence. He diagnosed plaintiffs as suffering from a variety of illnesses and harmful conditions, and concluded that these conditions were caused by exposure to PCBs.
The nine plaintiffs represented by D. Bruce Hanes relied on the testimony of G. John DiGregorio, M.D., Ph.D. Dr. DiGregorio is a clinical pharmacologist who received a degree from Hahnemann University. The Hanes plaintiffs, residents of properties adjacent to the railyard, claim to have been injured because defendants permitted PCBs to flow onto these properties, thereby causing plaintiffs to inhale PCB dust and ingest fruits and vegetables grown in the soil of their PCB-contaminated gardens. In formulating his opinions as to these plaintiffs, Dr. DiGregorio relied on medical history questionnaires filled out by plaintiffs themselves, laboratory tests revealing abnormal PCB blood levels in certain plaintiffs,*fn9 and scientific literature on the harmful effects of PCBs to both humans and animals. He performed no physical examinations. He opined that five of the nine Hanes plaintiffs suffered from specific injuries caused by PCBs; that all nine suffered from anxiety of contracting diseases in the future based on their exposure to PCBs; and that all nine were at increased risk of contracting future diseases because of their exposure. DiGregorio's testimony as to exposure was based largely on the statements of plaintiffs themselves and the results of laboratory tests revealing abnormal blood burdens of PCBs in various plaintiffs.
Although these expert witnesses were the only ones whose opinions were discovered pursuant to the case management order, they are not the only experts upon whom the plaintiffs rely. In response to the defendants' joint motion for summary judgment, plaintiffs submitted the affidavits of four additional experts: Ian C. T. Nisbet, Ph.D.; Robert K. Simon, Ph.D.; Benjamin Calesnick, M.D.; and William J. Nicholson, Ph.D.
Dr. Nisbet, who received his Ph.D. in physics from Cambridge University in 1958, currently serves as the president of a scientific consulting firm. He has published numerous articles in the fields of human exposure to chemicals and the assessment of associated health risks. Dr. Nisbet submitted an affidavit containing his opinions that (1) the defendants' estimates of the background PCB exposure level in the United States, as well as the studies upon which these estimates were based, are mistaken; (2) the correct background level, which should be determined by an adipose to blood ratio calculation, is much lower;*fn10 (3) many plaintiffs' exposures exceed the lower level; and (4) there are serious health hazards posed by exposure to PCBs.
Dr. Simon, who describes himself as "a professional industrial hygienist, toxicologist, and forensic analytical chemist," received his Ph.D. from the University of Maryland. The opinions contained in Dr. Simon's affidavit closely parallel those expressed by Dr. Nisbet, with varying degrees of emphasis.
Dr. Calesnick is a pharmacologist who received his medical degree in 1944 from Hahnemann Medical College, where he currently serves as a professor of medicine and as the director of Hahnemann's Division of Human Pharmacology. His resume lists one hundred published articles, as well as numerous academic and professional honors. Dr. Calesnick performed physical examinations and several laboratory tests on the Kohn/Klehr plaintiffs. He concluded summarily in his affidavit that these plaintiffs require medical surveillance as a consequence of their exposure to PCBs at Paoli.
The final affidavit offered in response to the summary judgment motion was that of Dr. Nicholson, a physicist who received his Ph.D. from the University of Washington in 1960 and is currently employed as a professor of community medicine at Mount Sinai School of Medicine in New York City. He has published over seventy articles and has served on various professional and governmental committees. Nicholson's affidavit advances two major theses: (1) contrary to the assertions of defendants and their experts, the epidemiologic studies conducted to date do support a conclusion that PCBs are causally associated with adverse health effects to humans; and (2) defendants and their experts are incorrect in asserting that animal carcinogenicity studies have little relevance for estimating carcinogenicity in humans.
In order to support his first thesis, Dr. Nicholson conducted a "meta-analysis," in which he combined the results of numerous epidemiologic surveys in order to achieve a larger sample size, adjusted the results for differences in testing techniques, and drew his own scientific conclusions. Specifically, he concluded that the results of the various surveys, considered as a whole, show that exposure to PCBs can cause liver, gall bladder and biliary tract disorders. Nicholson maintains that this is true even though none of the individual surveys supports such a conclusion when considered in isolation.
B. The Defendants' Submissions
Defendants' view of the case, as encapsulated in their joint motion for summary judgment, is that plaintiffs "failed to submit competent evidence creating a genuine issue of material fact concerning either of two essential elements on which plaintiffs bore the burden of proof: abnormal exposure, and causation." Appellees' Br. at 36. In support of this assertion, defendants adopted a two-pronged approach. First, they vigorously attacked plaintiffs' expert testimony and sought to have it excluded under Fed. R. Evid. 702, 703, and 403. Second, defendants submitted studies and expert testimony of their own on both exposure and causation issues. Because the case was resolved at the summary judgment stage, where credibility determinations are inappropriate, the latter evidence is significant only insofar as it relates, within the contours of our Rule 703 jurisprudence, to whether certain of plaintiffs' expert opinions should have been excluded because they were not based on facts or data reasonably relied on by experts in the field.
On the question of exposure, defendants attack the opinions of both Dr. Allen and Dr. Barsotti. Defendants submit that Dr. Allen's testimony should not be considered because his data and methodology were unreliable. They assert that Dr. Allen ignored the actual measured body samples of PCB exposure, and instead attempted to calculate exposure levels from levels of PCBs in the soil by using a formula "of his own devising." Dr. Allen's opinion is unhelpful, defendants say, because he was unable to provide "an exact calculation of the PCB dose received by the inhabitants." Further, defendants submitted the affidavit of a physical chemist and chemical hazard control specialist, Neil Jurinski, Ph.D., who expressed the view that Dr. Allen's soil-to-air migration hypotheses were "pure speculation unsupported by the data available or by scientific principles," and that they "were not arrived at by using accepted scientific methods."
Dr. Barsotti, who sought to show that plaintiffs were exposed to PCBs that came specifically from the Paoli Railyard, was subjected to similar methodological criticism for her "fingerprinting" method of gas chromatography. Defendants contend that Dr. Barsotti lacked experience in reviewing chromatographic tracings of human blood for evidence of PCBs, pointing out that Barsotti had never before attempted to compare soil chromatograms with human blood chromatograms. They further criticize Barsotti for having claimed to be able to match "early emerging peaks" in certain PCB isomers, because she later conceded that it was impossible for her to do so, having failed to use the proper equipment. Defendants also attack Barsotti's procedures as impossible to replicate, because she kept virtually no record of either her procedures or the basis for her conclusions. She was, they note, unable to identify any particular soil sample which was compared with any particular plaintiff; neither could she produce the specific chromatograms she used to compare plaintiffs' PCB blood levels to those of the unexposed population or at the railyard.
Defendants further attack Dr. Barsotti's opinions because, although she could not "think of anybody" who had ever done the analysis she purported to do in this case, she pursued her own methods, and ignored the body of existing data, "including the Public Health Service's Paoli Study, which concluded that it was scientifically impossible to determine that the Paoli Yard rather than the environment in general was the source of the residents' exposure." Appellee's Br. at 19. In addition, defendants presented their own expert, Dr. Raymond Harbison, a professor of toxicology and pharmacology, who concluded that "Dr. Barsotti lacks the requisite experience in reading and interpreting human and soil chromatograms to be able to perform the type of analysis that she purported to perform," and that "if in fact Dr. Barsotti did what she claims, she would be the first person to do this." With regard to the validity of Barsotti's experimental procedures, Dr. Harbison opined that it is impossible to identify the source of such low PCB levels, that the equipment used could not support Barsotti's analysis, and that the experiments lacked control and have not been replicated. He therefore dismissed Barsotti's results as being scientifically invalid.
Defendants also attacked Barsotti's opinions on causation, claiming that because she is not a physician, she is unqualified to make the differential medical diagnoses that defendants assert are critical to a finding of causation. Further, they argue that it was inappropriate for Dr. Barsotti to offer opinions on causation without ever having physically examined a single plaintiff. They point out that each of her nineteen scientific reports, which represent her conclusions on nineteen plaintiffs, is identical for the first fourteen pages. Barsotti described this as "boiler plate background information" on PCBs. Each report then contains only one or two additional paragraphs, which list the alleged injuries of the individual plaintiff and conclude "to a reasonable scientific certainty" that they were caused by PCBs.
In support of their challenge to Dr. Barsotti's expertise and conclusions, defendants offered the affidavits of their own experts.*fn11 These experts concluded generally that Dr. Barsotti is not qualified to form opinions on medical causation, that the opinions she did form lack evidentiary support and would not withstand review by experts in the field, and that her opinions are therefore not based upon known science or medicine. Defendants also assail Dr. Barsotti's opinion that plaintiffs, including one two-year-old child, suffer from increased fear of illness and are emotionally distressed. They note that she offered this opinion, having spoken only to one plaintiff over the telephone, and without having met or examined any of the plaintiffs. Further, defendants contend that she performed no psychiatric evaluations or tests, and that she is unqualified to do so.*fn12
Defendants took a similar tack in attempting to discredit the opinions of Dr. Zahalsky, attacking first his qualifications as an expert, and then challenging the bases for his scientific opinions that plaintiffs had suffered immune system damage as a result of having been exposed to PCBs. Insofar as Dr. Zahalsky's credentials are concerned, defendants point out that he claimed a specialty in immunology, but had completed only one graduate-level course that included immunology. Zahalsky conceded his lack of expertise in epidemiology, toxicology, and medicine, and admitted that because he is not a medical doctor, he is not qualified to examine patients, perform clinical tests, or render differential diagnoses.
At his deposition, Dr. Zahalsky offered diagnoses of immune system damage in a number of plaintiffs, even though he had not tested any of the plaintiffs, and instead simply assumed that plaintiffs had elevated PCB exposure. He admitted that his opinions could be validated only by a series of tests that he designed, and further noted that these tests had not yet been performed. In attempting to show the lack of scientific approval for the proposition that PCBs damage the immune system, defendants point to Zahalsky's own somewhat cryptic statement that if his tests should support such a conclusion, "then I will have done something with the clinical immunologists that has not yet been done."
Defendants also noted that all of the studies relied upon by Zahalsky were either animal studies or human studies arising from the Yusho and Yu Cheng incidents. Defendants argue that reliance upon the Yusho and Yu Cheng studies is scientifically inappropriate because the PCB contamination in those incidents was intermingled with exposure to and ingestion of PCDFs, which defendants characterize as a far more toxic chemical. Indeed, even one of plaintiffs' experts opined that the toxicity of PCDFs is "500 to 2000 times greater" than that of PCBs. Further, they rely on a Public Health Service comment that there appears to be general agreement in the scientific community that PCDFs "contributed significantly" to the adverse health effects analyzed in the Yusho and Yu Cheng studies. Moreover, Zahalsky was generally unable to specify supporting authorities for his opinions, and often simply assumed that the existence of symptoms in plaintiffs evidenced exposure to PCBs. Zahalsky himself characterized his opinion as a "hypothesis" or "statement of expectation."
Defendants also submitted an affidavit signed by twelve physicians and scientists who had reviewed all existing medical and scientific knowledge regarding PCBs. The affidavit criticized Zahalsky's results, noting that "one may not conclude to a reasonable degree of medical and scientific certainty that PCBs can cause immune system disorders." Several of the individual defense experts then criticized Zahalsky's work directly. One expert stated that because Zahalsky is neither an immunologist nor a medical doctor, he is not qualified to diagnose human illness. Another expert decried as false the claim that the scientific literature supported Zahalsky's position, and asserted that Zahalsky's attempted extrapolations from the existing literature were "scientifically improper." Zahalsky's methodology was described as "scientifically inadmissible" because of its failure to obtain basic data, its lack of control groups, and its inadequate histories. And one expert opined that "no doctor would rely on the tests described in the Zahalsky affidavit for any purpose whatsoever."
Defendants likewise criticized the opinions of Dr. Shubin, who offered causation testimony in the Cunningham and Reid cases. Defendants objected to Shubin's conclusions that plaintiffs' injuries were caused by PCBs because: (1) his diagnosis conflicted with diagnoses of other physicians who had previously examined plaintiffs, and (2) his diagnosis was based on a method that improperly assumed the injuries to be caused by PCBs. As with Dr. Barsotti, defendants also registered more particular complaints regarding the individual diagnoses. When Shubin cited PCBs as the cause of Matthew Cunningham's hypertension, defendants argued that he had failed to consider other factors, including Cunningham's family history of hypertension, his obesity, and his high blood sugars. In addition, Shubin was unable to point to any studies showing a direct causal relationship between PCB exposure and hypertension. Shubin attributed Cunningham's Parkinson's Disease and eventual death to PCB exposure, even though previous doctors had determined the Parkinson's Disease to have been caused by the use of psychotropic drugs, and even though Shubin did not know the circumstances of Cunningham's death.
Defendants cited similar flaws in Shubin's diagnoses of Bessie Cunningham and William Reid. Shubin concluded that Ms. Cunningham's four spontaneous abortions were related to PCB exposure, although he knew neither the circumstances surrounding the abortions, nor even when in the past forty years they had occurred. Shubin opined that a host of illnesses allegedly suffered by William Reid were the result of PCB exposure, although he found no PCBs in Mr. Reid's blood, and did not rule out other possible causes, such as smoking. Defendants also objected to Shubin's reliance on animal studies and the Yusho and Yu Cheng incidents.
Some of the same experts who criticized Dr. Barsotti's work also criticized Dr. Shubin's. They characterized his opinions as "conjectural guesses," which "fail adequately to consider multiple etiologic factors, as well as obvious differential diagnoses," and "would not withstand review by a qualified panel of his peers." One expert stated that because Shubin's opinions "have no basis in factual observation or in a plausible hypothesis, [they are] devoid of scientific justification."
Similarly suspect, according to defendants, are the opinions of Dr. DiGregorio, whom defendants criticize for offering a "certain" opinion that plaintiffs suffered from anxiety and fear of future harm as a result of PCB exposure, even though he never conducted a mental status examination, took a psychiatric history, or reviewed any medical records. Indeed, DiGregorio acknowledged that his diagnoses were only preliminary, and that further testing would have to be conducted. In his own words, DiGregorio saw each plaintiff only "for a brief period of time," "never reviewed any medical records of anyone," and was unable "to establish any physical findings yet." He nevertheless offered the opinion, with respect to five of the plaintiffs, that "until otherwise proven," see whatever ailments they had were caused by PCBs. Defendants argue strenuously that these opinions are improper, not only because they are based on insufficient information, but also because, in every case, the doctor failed to rule out other possible causes for the injuries. They view the failure to conduct a conclusive differential diagnosis as a fatal flaw in DiGregorio's opinion.
Defendants also objected to the opinions set forth in each of the four supplemental affidavits offered by plaintiffs in response to the joint motion for summary judgment. Defendants criticized Dr. Nisbet as being unqualified to offer an opinion that was, in any event, unsupported. Nisbet's attempt to use a conversion factor to determine PCB blood level from adipose tissue levels was, defendants argue, indefensible because it was based on no published or peer-reviewed studies, and is in fact contradicted by both the Public Health Service's Toxicological Profile, and plaintiffs' own expert, Dr. DiGregorio. Defendants characterize Nisbet's method as "assumptions plus arithmetic," and assert that his conversion factor is proven wrong by physical evidence that plaintiffs whose blood levels and adipose tissue levels were measured did not reflect the blood levels that would have ...