Holding that the jury’s causation finding was based on legally insufficient evidence, a divided Texas Supreme Court has affirmed a take-nothing judgment in a case seeking to hold Georgia-Pacific Corp. liable for Timothy Bostic’s death from mesothelioma. Bostic v. Georgia-Pacific Corp., No. 10-775 (Tex., order entered July 11, 2014). So ruling, the court explored the use of the substantial factor and but-for causation tests in the context of asbestosis and mesothelioma cases, finding that the plaintiffs “were required to establish substantial factor causation, but were not required to prove that but for Bostic’s exposure to Georgia-Pacific’s products, he would not have contracted mesothelioma.”

Brought by Bostic’s relatives after his death, the case was originally tried in 2006, and a jury found Georgia-Pacific 75 percent liable for Bostic’s asbestos exposure. The trial court awarded the plaintiffs an amended judgment of approximately $11.6 million, but the court of appeals rendered a take-nothing judgment after determining that the causation evidence was legally insufficient.

The Texas Supreme Court first rejected the plaintiffs’ argument that showing “any exposure” to asbestos in materials provided by the defendant is sufficient to prove causation of the asbestos-related disease. The plaintiffs argued that because mesothelioma can be caused by small exposures to asbestos—as opposed to asbestosis, which requires large asbestos exposures before the disease develops— “any exposure” caused by Georgia-Pacific should be sufficient to prove liability. The court could not reconcile this argument with the fact, acknowledged by plaintiffs’ experts, that asbestos is “very plentiful in the environment” in cities. “If any exposure at all were sufficient to cause mesothelioma,” the court concluded, “everyone would suffer from it or at least be at risk of contracting the disease.”

The court then determined whether to apply the “overlapping concepts” of but-for causation and the substantial factor test. The court of appeals’ decision quoted Borg Warner Corp. v. Flores, 232 S.W.3d 765 (Tex. 2007), but appended but-for language to the end: “‘In asbestos cases, then, we must determine whether the asbestos in the defendant’s product was a substantial factor in bringing about the plaintiffs’ injuries,’ and without which the injuries would not have occurred.”

The Texas Supreme Court rejected this appended language, holding that “in products liability cases 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.” Further, the court noted that “in multiple-exposure cases the plaintiff may find it impossible to show that he would not have become ill but for the exposure from that defendant.” To support its reasoning, the court pointed to a similar conclusion from the Virginia Supreme Court, the Restatement Second of Torts’ recognition that cases involving multiple causes of injury may require an alternative to strict but-for causation, and its own reasoning in Flores. The court held that the court of appeals erred in stating that the plaintiff must show but-for causation, but it still agreed that the evidence was legally insufficient to prove liability.

The court also discussed the application of Merrell Dow Pharmaceuticals, Inc. v. Havner, 953 S.W.2d 706 (Tex. 1997). Under Havner, “where direct evidence of causation is lacking, scientifically reliable evidence in the form of epidemiological studies showing that the defendant’s product more than doubled the plaintiff’s risk of injury” may be used to show legal causation in toxic tort cases. “These principles should apply to asbestos cases,” the court held.

According to the court, “[T]he case as Plaintiffs tried it to the jury (1) relied on opening and closing arguments and on multiple experts who repeatedly testified that any exposure to asbestos should be considered a cause of Bostic’s disease, (2) failed to quantify, even approximately, the aggregate dose, (3) failed to quantify, even approximately, the dose attributable to Georgia-Pacific, and (4) failed to show that the dose fairly assignable to Georgia-Pacific more than doubled Bostic’s chances of contracting mesothelioma.”

A concurring justice argued that the court’s decision “set the evidentiary bar too high for future claimants” by changing the preponderance of the evidence standard in mesothelioma cases to incorporate Havner. “While the bulk of epidemiological studies appear to focus on occupational exposure, properly substantiated extrapolations can bridge the gap between those studies and the plaintiff who contracted mesothelioma from occasional exposure to asbestos,” she wrote. Still, the justice concurred with the majority, finding that the plaintiff in this case failed to bridge that gap.

Three dissenting justices would have found that Bostic’s submitted evidence was sufficient to sustain the jury verdict, in part because they believed that low asbestos exposures are sufficient to cause mesothelioma and, as such, evidence of any exposure should be sufficient to establish liability. The justices also disagreed that Havner applies to determine substantial factor causation, concerned that “the Court’s opinion today suggests that Havner is the exclusive measure of proof with respect to those questions in every toxic tort case.” According to the dissent, “After today, the law in these types of cases will be that exposure to a single defendant’s product is a ‘substantial factor’ in bringing about a plaintiff’s injury only when that exposure would have been sufficient, by itself, to more than double the plaintiff’s risk of developing a particular disease.”