Opinion ID: 3050124
Heading Depth: 4
Heading Rank: 3

Heading: Medical Screening Study: ATSDR and Peipins

Text: Publication
In 2000-2001, the Agency for Toxic Substances and Disease Registry (“ATSDR”) conducted a medical screening study in Libby (the “ATSDR Report”) to detect pleural abnormalities in Libby residents and to inform priority-setting in EPA’s asbestos clean-up operation. The study entailed interviewing and medically testing individuals who had lived, worked, attended school, or participated in other activities in Libby for at least six months before 1990. Questions were asked to identify individuals who had accessed potential “exposure pathways” to asbestos and vermiculite prior to DecemUNITED STATES v. W. R. GRACE 12701 ber 31, 1990. For example, “pathways” included employment at W. R. Grace, living with W. R. Grace workers, using vermiculite for gardening, and engaging in recreational activities in certain locations known to contain vermiculite. Information about other basic demographic variables and risk factors was also gathered, e.g., age, sex, smoking status, history of pulmonary disease and various other self-reported health conditions. ATSDR published an initial report of the study’s findings in February 2001. The complete results of the study (the “Peipins Publication”) were published in November 2003 in Environmental Medicine, a peer-reviewed journal. The Peipins Publication analysis used regression modeling to estimate the risk of respiratory abnormalities for each of the exposure pathways while controlling for all other pathways and other established and suggested risk factors. The study showed that certain factors — including exposure to particular pathways — were associated with respiratory illness and abnormalities. The factors most strongly associated with abnormalities were: being a former W. R. Grace employee, being older, having had household contact with a former W. R. Grace worker, and being male. (The study also demonstrated “a statistically significant increase in the prevalence of pleural abnormalities with an increasing number of exposure pathways.” While “participants reporting more pathways might be expected to have more cumulative exposure than would those reporting fewer pathways,” this was not data gathered by the study; the study identified avenues for exposure but did not quantify the duration or intensity of individuals’ exposures. Both the interim ATSDR Report and the final Peipins Publication noted that the study had no control group and “no directly comparable Montana or U.S. population studies [were] available.” The researchers were able to compare the data gathered with studies of other groups with substantive work-related asbestos exposure. The levels of pleural abnor12702 UNITED STATES v. W. R. GRACE malities were higher in Libby than in studies of other groups, but the study did not engage in any direct quantitative comparison.17 On May 31, 2006, defendants filed a motion in limine “to exclude expert evidence relating to the ATSDR Medical Testing Program.” Defs’ Mot. in Limine Re: ATSDR (Docket # 500, 502). The district court characterized the motion as one to exclude “any evidence or expert testimony relating to” the medical screening study conducted in Libby by the Agency for Toxic Substances and Disease Registry. ATSDR Order at 1. The government did not object to the court’s characterization of defendants’ motion. On August 31, 2006, the district court granted defendants’ motion. The court ruled that the ATSDR Report and Peipins Publication, and any expert testimony based thereon, were excluded under Rules 403 and 702 for any purpose relating to the Clean Air Act knowing endangerment counts. Id. at 31.
[16] The district court acted within its discretion in excluding the ATSDR Report and Peipins Publication themselves under Rule 403 for purposes of the knowing endangerment counts. There are limits to the probative value18 of the particu17 The results of the ATSDR Report were also compared with “control groups or general populations found in other studies.” That comparison showed that the levels of pleural abnormalities were also higher in Libby for those who claimed “no apparent exposure” to particular pathways than subjects in other studies. This supported the study’s conclusion that it was unlikely that there were individuals in Libby who had not been exposed to some degree. 18 The study demonstrated an association between negative health outcomes and an individual’s unquantified exposure to vermiculite via particular “pathways” prior to the statutory period. The existence of association — and not causation — goes to the probative value of the evidence. The reported findings did not indicate that all exposure pathways were significantly associated with lung abnormalities (for example, gardening with UNITED STATES v. W. R. GRACE 12703 lar correlations the ATSDR Report revealed and potentially prejudicial aspects to the data. Moreover, the government failed to contest the district court’s undue prejudice conclusion. Because Rule 403 requires the district court to balance the probative value and the prejudicial effects of a piece of evidence, failure to raise and argue prejudice generally waives the argument. See United States v. Wilson, 966 F.2d 243, 24546 (7th Cir. 1992). [17] However, in excluding this evidence from informing expert opinion and testimony, the district court erred. The expert is, in the first instance, the judge of what resources would help him to form an opinion, and he can filter out as irrelevant prejudicial information. The trial judge is to assure the reliability of evidence by vetting under Rule 703 the bases underlying the expert’s testimony and by examining under Rule 702 the expert’s methodology. Here, however, the trial judge misapplied Rule 702 and replaced inappropriately the Rule 703 analysis with one under Rule 403. To begin, the district court concluded that the ATSDR medical screening program and resulting analyses did not establish a causal link between exposure to Libby’s vermiculite and the development of asbestos-related disease. The ATSDR Report acknowledged repeatedly that the testing program was not designed as an epidemiological study to show causality. Notably, there was no internal control group and the participants were self-selected, rather than randomly selected. In light of this, the district court concluded that the data could not provide experts with a reliable basis for opining as to cauvermiculite is not one of the factors mentioned as one being associated with such abnormalities). Because the data were gathered before the statutory period, it is questionable how reliable a basis they provide for drawing conclusions about the extent of the dangers posed by ambient releases during the statutory period, i.e., concentration or duration of releases. However, this is more an issue for the expert than the court. 12704 UNITED STATES v. W. R. GRACE sality (i.e., the danger posed by the releases from Libby vermiculite). Nonetheless, one of the main objectives of the ATSDR Report was to examine the association between pleural and interstitial abnormalities and participants’ exposure histories — measured in broad terms by the participants’ overall contact with exposure pathways. As the district court acknowledged, the government’s experts did not claim that they intended to use the study to show causation, but rather indicated that they would rely on the evidence to show that there were some associations or correlations between exposure to vermiculite in Libby and pleural abnormalities. The district court took the view that the jury would be unlikely to distinguish between evidence of an association and evidence of causation and therefore would likely be misled, and would place undue reliance on the evidence. In this respect, the court substantially underestimated the capacity of jury instructions to distinguish these relationships, and the potential efficacy of a limiting instruction. Further, the fact that a study is associational — rather than an epidemiological study intended to show causation — does not bar it from being used to inform an expert’s opinion about the dangers of asbestos releases, assuming the study is “of the type typically relied upon” by experts in the field. Fed. R. Evid. 703. Of course, the expert’s opinion testimony must satisfy the requirements of Rule 702—but that requires consideration of the overall sufficiency of the underlying facts and data, and the reliability of the methods, as well as the fit of the methods to the facts of the case. Fed. R. Evid. 702. Here, the district court failed to consider the Rule 702 requirements with regard to causation. Instead, as with the historical testing, the court conducted a document-bydocument Rule 702 analysis that deconstructed the experts’ testimony in a manner not contemplated by Rule 702. MoreUNITED STATES v. W. R. GRACE 12705 over, the study, which was published in a peer-reviewed journal and relevant to association, is adequate under 702. The study’s failure to establish causation goes to the weight it should be accorded, but does not mean that an expert could not rely on it in forming an opinion. Nor did the district court consider the possibility of expert reliance on the ATSDR Report without disclosure of the study itself to the jury, as provided for by Rule 703 (“If of a type reasonably relied upon by experts in the particular field in forming opinions or inferences upon the subject, the facts or data need not be admissible in evidence in order for the opinion or inference to be admitted.”). In fact, the district court generally failed to conduct a 703 analysis, such as considering whether this study was “of the type” relied upon by experts in the field, or whether the ATSDR Report’s “probative value . . . substantially outweighs [its] prejudicial effect.” Fed. R. Evid. 703. [18] Instead, the district court excluded expert testimony regarding the ATSDR Report under Rule 403. This ruling improperly replaced 703 balancing with 403 balancing, cf. Fed. R. Evid. 703 (providing balancing test applicable to expert testimony), and the exclusion of the ATSDR Report and Peipins Publication as bases for expert testimony or opinion formation was error. While Rule 403 supplies a basis for holding the underlying ATSDR Report inadmissible, it does not contemplate barring an expert from relying on it. Cf. Fed. R. Evid. 403. The exclusion of the ATSDR Report and the Peipins Publication from expert consideration and testimony was error, and thus we reverse that part of the ATSDR Order.