A trial court in the Western District of Washington recently rejected the “each and every exposure” and “cumulative exposure” causation theories often relied on by asbestos plaintiffs.
In Barabin v. Scapa Dryer Fabrics 2018 U.S. Dist. LEXIS 22725 (W.D. Wash. Feb. 12, 2018), the defendant moved to exclude the plaintiff’s four medical causation experts (Brodkin, Smith, Tarin, and Cohen). Each of these experts offered some version of the “each and every exposure” theory, which these experts presented in the form of two types of opinions:
1.That every exposure (or every exposure above ambient level) to asbestos is a substantial factor in causing mesothelioma; and
2.That every exposure, no matter how small, contributes to the overall cumulative dose causing mesothelioma, therefore every exposure is causative.
The defendant argued that both opinions were inconsistent with substantial factor causation. Washington state law controlled, but the court also looked
to both maritime and non-maritime opinions including McIndoe, Lindstrom and the recent Krik decision in the 7th Circuit for guidance on this issue. The court strongly rejected any variation of the every exposure/cumulative exposure theory as inconsistent with
substantial factor causation, explaining that “such a theory is not tied to the severity of exposure and instead is based on a view that every exposure
is a substantial contributing factor to any resulting mesothelioma. In other words, as long as the plaintiff later contracts mesothelioma, any exposure
he or she may have had automatically becomes a substantial factor in the contraction of that disease. The imposition of a de minimis threshold
does not save this theory. Neither variant of the theory is based on sufficient supporting facts and data, nor can either variant be tested or have
a known error rate.”
The court then analyzed the particular opinions of the plaintiff’s experts:
Dr. Carl Brodkin offered what is called an “identified exposure” theory, which considers five separate factors in determining the substantiality of an
alleged exposure. The court concluded that this was not an “each exposure” theory in disguise, because Brodkin’s use of five determinative factors
prevented all exposures from automatically qualifying as substantial factors.
Dr. Allan Smith offered what can fairly be called a “cumulative exposure” theory (i.e. that each inhalation of asbestos fibers contribute to the causal
dose, and each is therefore causative). The court found this directly inconsistent with substantial factor, and unreliable under Daubert/Rule
Dr. David Tarin offered a more nuanced opinion. He claimed that the cumulative exposure to all forms of asbestos contributed to the induction and propagation
of the tumor. However, he did not actually say that because every exposure contributes to the total dose, that every exposure must then be a substantial
facture in causing the disease. The court was wary of how fine this distinction was, and limited Tarin’s testimony to prevent any opinion on the individual
exposures that made up the cumulative exposure.
Dr. Richard Cohen opined that any exposure above ambient levels would be a substantial factor in causing the disease. The court found that Cohen relied
on both the every exposure and cumulative exposure theories, and excluded his testimony as unreliable.
Though only a federal trial court order, this decision will nevertheless be useful in forcing plaintiffs’ experts to offer more specific and detailed opinions about exposures to defendants’ products, instead of relying on broad and general causation opinions.