Bostic v. Georgia-Pacific Corp.
Supreme Court of Texas, No. 10-0775 (July 11, 2014)
Justice Willett (Opinion), Justice Guzman (Concurrence), Justice Lehrmann (Dissent)
In a much-anticipated decision, a divided Supreme Court of Texas clarified the causation standard in asbestos-related mesothelioma cases. The Supreme Court held, among other things, that the Borg-Warner Corp. v. Flores causation standard for asbestosis cases also applies in cases based on mesothelioma.

Timothy Bostic’s survivors sued Georgia-Pacific and 39 other defendants for wrongful death based on negligence and products liability theories after Bostic died of mesothelioma, a cancer caused by asbestos. As a child, Bostic was exposed to asbestos from his father’s clothing, and as an adult from asbestos encountered in his own work. The jury found Georgia-Pacific liable and allocated 75% responsibility to the company. The other 25% was apportioned to Knox Glass Company, one of Bostic’s former employers that had already settled. The court of appeals reversed the trial court’s judgment and rendered a take-nothing judgment in favor of Georgia-Pacific, concluding that the plaintiff’s evidence of causation was legally insufficient. After analyzing the standard for causation, the Supreme Court affirmed the appeals court’s conclusion that there was legally insufficient evidence to establish causation.

The Texas Supreme Court addressed the causation standard in asbestos-related cases in Borg-Warner v. Flores. In that case, the Court held that a plaintiff must prove a defendant’s product was a “substantial factor” in causing the plaintiff’s disease; mere proof that the plaintiff was exposed to “some” respirable asbestos fibers traceable to a defendant is insufficient to establish causation. But the plaintiff in Flores had asbestosis, a disease that is contracted through heavy exposure to asbestos. Bostic’s survivors argued that because mesothelioma, as opposed to asbestosis, can be caused by low levels of asbestos exposure (i.e., there is no safe level of exposure) the court of appeals erred by holding Flores requires a defendant’s product to be a substantial factor in causing mesothelioma.

The Supreme Court held that Flores’s substantial-factor standard—that the “defendant’s conduct has such an effect in producing the harm as to lead reasonable men to regard it as a cause”—applies to mesothelioma cases. Mere proof of “some exposure” or “any exposure” is insufficient to establish causation. The likelihood of contracting asbestosis and mesothelioma increases with the dose, and the any-exposure theory ignores this evidence and instead would impose absolute liability on any company whose asbestos-containing product the plaintiff ever encountered throughout his lifetime. Furthermore, the any-exposure approach negates a plaintiff’s burden to prove causation by a preponderance of the evidence. Thus, when direct evidence of exposure exists, a plaintiff must quantify the approximate dose of exposure to the defendant’s product based on frequency, regularity, and proximity, although the exposure does not have to be established with mathematical precision.

The Supreme Court did disagree with the court of appeals’ holding to the extent it might be interpreted as requiring a plaintiff to prove but-for causation, i.e., that without exposure to the defendant’s product the plaintiff would not have contracted mesothelioma. When there are multiple sources of asbestos, a but-for causation requirement could make it impossible for the plaintiff to prove causation for any individual product due to the disease process’s long latency period, the inability to trace precisely which fibers caused the disease, and the inability to trace the product from which the fibers emanated. 

The Court further explained the meaning of substantial-factor causation in asbestos cases. Based on its holding in Merrell Dow Pharmaceuticals, Inc. v. Havner, the Supreme Court held that, in the absence of direct proof of causation, establishing specific causation against a defendant in an asbestos-related disease case requires scientifically reliable proof that the plaintiff’s exposure to the defendant’s product more than doubled his risk of contracting the disease. An expert’s conclusion to this effect must be based on epidemiological studies or similarly reliable scientific testimony. However, in cases involving multiple sources of exposure to the same toxin, the plaintiff does not have to identify every possible source of exposure and disprove that those exposures caused his disease. But, when evidence of exposure to other products or other sources is introduced, and the defendant’s contribution is trivial, a doubling of the risk may not establish substantial-factor causation “if reasonable persons would not regard the defendant’s product as a cause of the disease.”  

Justice Guzman concurred, agreeing with the majority that Bostic did not produce epidemiological studies that comported with Havner and that he failed to prove his approximate dose of exposure to Georgia-Pacific products. But she disagreed with the majority’s methodology for establishing causation because its requirements may foreclose recovery in occasional-exposure mesothelioma cases. Justice Guzman also rejected the dissent’s approach, arguing that it erred in the opposite direction, lowering the plaintiff’s burden of proof below a preponderance of the evidence. 

Justice Lehrmann dissented, joined by Justices Boyd and Devine, arguing that the majority ignored reliable scientific research that demonstrates even low levels of exposure to asbestos can cause mesothelioma. The majority’s holding, that a doubling of the risk is required to prove substantial-factor causation, inappropriately and illogically conflates Havner’s alternative measure of proof for specific causation with substantial-factor causation when multiple manufacturers contribute to a plaintiff’s exposure. The majority’s causation approach requires a plaintiff to demonstrate that every culpable defendant’s product independently doubled the risk of contracting mesothelioma, the dissent argued, which forecloses recovery for plaintiffs exposed to multiple sources that were not alone sufficient to cause his or her disease.