Recently in Asbestos Columns, published by Harris Martin, I authored an article on the causation of lung cancer asking how much does asbestos really contribute. Courts that look at the issue of causation in asbestos cases are now less likely to allow testimony from plaintiff’s experts that any exposure above background will substantially contribute to cause an asbestos related disease and more likely to require a plaintiff to prove that the alleged exposure attributable to a defendant was sufficient to cause his disease.
I then ask how the science is applied. Based upon the epidemiology of lung cancer and asbestos exposure, plaintiffs should be required to prove that plaintiff had sufficient exposure to cause asbestosis and, in fact, has asbestosis of the lung parenchyma, not just pleural plaques or thickening. Studies to the contrary, almost always by those testifying for plaintiffs, are unreliable because the studies do not properly control for cigarette smoking. Specifically those who smoke for a longer duration are many times more likely to get lung cancer. These studies by pro-plaintiff authors do not control for duration of cigarette smoking.
Plaintiff’s often cited mantra that cigarette smoking and asbestos exposure have a synergistic effect multiplying the risk of lung cancer more than fifty times has been largely disproven. The studies that were argued as support for the synergistic effect were based exclusively on high exposures such as exposures of laggers before 1968. More recent studies show the effect is rather just additive. A life-long smoker gets 1000s of times greater risk from his smoking than from a few weeks working at a plant or with a particular product. Just because plaintiff does not smoke does not mean that his alleged asbestos exposure caused his lung cancer. More lung cancers occur in persons who do not smoke and are not exposed to asbestos than occur in persons exposed to asbestos. Finally, plaintiffs are always quick to point out that the risk of lung cancer declines after a person stops smoking. The same is true of asbestos exposure. In fact, based upon the science of how asbestos causes lung cancer and based upon epidemiological studies, more than 24 years after exposure to asbestos a person’s risk of lung cancer from his asbestos exposure declines to zero.
Defendants may want to consider pressing these arguments through motions for summary judgment, motions in limine, objections to opinions of plaintiff’s experts and requests for directed verdict.