In July the Texas Supreme Court handed down its long-anticipated decision regarding substantial causation in mesothelioma claims arising from exposure to asbestos. In Bostic v. Georgia-Pacific Corporation (No. 10-0775), a 40-year old worker died of mesothelioma. His family brought a wrongful death action against Georgia-Pacific and 39 other defendants, alleging that their products exposed the decedent to asbestos fibers that caused the disease. Specifically, plaintiffs claimed that Bostic had been exposed over a period of several years to drywall joint compound manufactured by Georgia-Pacific. After a jury found Georgia-Pacific 75% responsible for Bostic’s injury, the trial court awarded the plaintiffs $6.8 million in compensatory damages and $4.8 million in exemplary damages. The Fifth District Court of Appeals (Dallas) reversed and rendered judgment for Georgia-Pacific, finding the evidence of Bostic’s exposure to Georgia-Pacific’s products legally insufficient to support a finding of liability.
By a 6-3 majority, the Texas Supreme Court affirmed the Dallas Court of Appeals’ decision. Writing for the majority, Justice Don Willett conducted a careful analysis of Texas law governing proof of causation. The Court of Appeals ruled that Borg-Warner Corp. v. Flores, 232 S.W.3d 765 (Tex. 2007), which rejected the “any exposure” test in an asbestosis-disease case and required the plaintiff to prove that exposure to the defendant’s product was a substantial factor in causing the disease, likewise applied to mesothelioma claims. In Borg-Warner, the SCOT held that “proof of mere frequency, regularity, and proximity is necessary but not sufficient, as it provides none of the quantitative information necessary to support causation under Texas law.” Instead, the plaintiff must offer “defendant-specific evidence relating to the approximate dose to which the plaintiff was exposed, coupled with evidence that the dose was a substantial factor in causing the asbestos-related disease.” Borg-Warner, 772-73. In Bostic, the plaintiffs sought to distinguish Borg-Warner on the basis that, whereas heavy exposure to asbestos is necessary to contract asbestosis, a much smaller level of exposure to asbestos can cause mesothelioma. They argued that meeting the so-called “Lohrmann standard,” which requires mere proof of frequency, regularity, and proximity, should be sufficient to establish causation in a mesothelioma case. The SCOT disagreed.
To reach this decision, Justice Willett reviewed the expert testimony to the effect that mesothelioma, like asbestosis, is dose-related, and that the chance that someone will contract mesothelioma increases as the total dose of inhaled fibers increases. Under an “any exposure” or “some exposure” test propounded by the plaintiffs, strict and absolute liability would result against any defendant to whose asbestos-containing products a plaintiff has been exposed at any time for any duration. By the same logic, Justice Willett reasoned, minimal exposure to any carcinogen could become the basis for liability because in no case can science establish with absolute certainty the minimum dose of a carcinogen below which the risk of cancer approaches zero. Moreover, Texas law requires a plaintiff to prove by a preponderance of the evidence that the specific defendant’s product caused the plaintiff’s disease, not just that the plaintiff may have been exposed to the defendant’s product as well as other sources at some time in the past. Citing the Court’s landmark decision in Merrell Dow Pharmaceuticals, Inc. v. Havner, 953 S.W.2d 706 (Texas. 1997), Justice Willett opined that “even in mesothelioma cases, liability cannot be imposed on every conceivable defendant whose product exposed the plaintiff to some unquantified amount of asbestos, without something more” (11).
So what is that “something more”? The plaintiffs argued that under the Court of Appeals decision, they would have to prove that Bostic would not have contracted mesothelioma “but for” his exposure to Georgia-Pacific’s product. While agreeing with Georgia-Pacific that “but for” causation is generally subsumed into the test for substantial factor causation in tort cases, Justice Willett determined that “in products liability where the plaintiff was exposed to multiple sources of asbestos, substantial factor causation is the appropriate basic standard of causation without including as a separate requirement that the plaintiff meet a strict but for causation test” (15). Following Borg-Warner, the Court’s ruling thus appears to confirm an exception to “but for” causation limited to asbestos cases in which, as a practical matter, the long latency period of the disease and multiple sources of exposure make it difficult for the plaintiff to prove with precise specificity that the defendant’s fibers caused the plaintiff’s disease. Justice Willett went to great lengths in the opinion to square the Court’s ruling with the Restatement Third of Torts, which in several sections appears to recognize a somewhat less stringent substantial factor causation standard in multiple causation cases.
Justice Willett next engaged the question of the quantitative evidence necessary to prove substantial factor causation in asbestos cases. Once again turning to Havner, Justice Willett noted that scientific and epidemiological studies showing sufficient exposure to “more than doubling the risk may be supportive of legal causation, provided that other indicia of reliability are met” (24). In the absence of direct proof of causation, consequently, the Court ruled that in cases involving asbestos-related diseases, “the plaintiff must show scientifically reliable proof that the plaintiff’s exposure to the defendant’s product more than doubled his risk of contracting the disease. A more than doubling of the risk must be shown through reliable expert testimony that is based on epidemiological studies or similarly reliable scientific testimony” (26). The majority also decided that while a plaintiff is not required to quantify his or her exposure from every other possible source in order to establish the defendant’s liability, evidence that exposure to another source of a toxin “increased the chances [of contracting the disease] by a factor of 10,000,” the “trier of fact or a court reviewing the sufficiency of the evidence should be allowed to conclude that the defendant’s product was not a substantial factor in causing the disease” (28).
The Court then analyzed plaintiffs’ proof of causation against Georgia-Pacific. Plaintiffs offered proof of work history and expert testimony. The work history evidence did not reveal the duration of intensity of exposure in any of Bostic’s workplaces, but Bostic’s experts all testified that “each and every exposure” to asbestos caused his disease (35). Plaintiffs offered no evidence of quantifiable dose or even of approximate dose. Moreover, plaintiffs’ experts contradicted their own testimony regarding “each and every exposure” by admitting that asbestos diseases are dose-related. The Court further found that the epidemiological studies Bostic’s experts cited involved long-term occupational exposures that were not substantially similar to Bostic’s occasional exposure to Georgia-Pacific’s drywall joint compound in the course of helping his father with construction projects outside of his primary employment. The Court concluded that plaintiffs did not meet their burden of proving that Georgia-Pacific’s product was a substantial cause of Bostic’s disease.
Justice Lehrmann, joined by Justices Boyd and Devine, dissented. The dissent argues that the plaintiffs met their burden of proving substantial causation because they proved by reliable scientific evidence that asbestos causes mesothelioma, that asbestos caused Bostic’s mesothelioma, and that exposure to Georgia-Pacific’s product was “substantial” in relation to other sources. The dissent also complained that the majority used Havner’s standard of “doubling the risk” for evaluating expert testimony of disease causation.
In 2009 the Texas Legislature rejected legislation that would have adopted the Lohrmann standard of substantial factor causation in mesothelioma cases. The proposed legislation, backed by the asbestos plaintiff’s bar, attempted to pre-empt the SCOT’s consideration of Bostic and the application of Borg-Warner in mesothelioma lawsuits. Joined by other business groups, TCJL opposed this legislation on the basis that “dose matters” in mesothelioma cases in the same way it does in asbestosis cases, and that Borg-Warner represented the appropriate approach to substantial factor causation in all asbestos cases. The Court’s decision in Bostic affirmed this position and puts Texas in the forefront of national jurisprudence on this issue.