A Legal and Epidemiological Consideration of the Causal Relationship between Tobacco and Lung Cancer

This study reviewed issues including causality among tobacco companies’ illegal acts, smoking, and lung cancer occurrence. In tobacco lawsuits so far, the burden of proof regarding negligence and a causal relationship has fallen on plaintiffs, who are the injured party. However, since the legislation of the Product Liability Act, the possibility of mitigating plaintiffs’ burden of proof has opened up. Nevertheless, this alone cannot prevent the immense socioeconomic cost incurred due to smoking. It is legislatively necessary to enact a tobacco management law so that the no-fault liability of tobacco companies, which are the defendants, for compensation can be acknowledged. However, it is necessary to take supplementary measures through the social security system such as establishing the upper limits for liquidated damages in lawsuits and creating a relief fund for the victims of smoking. In addition, it is fundamentally necessary for courts to accept the methods for inferring causality that are based on the natural sciences and epidemiology in situations such as tobacco lawsuits, where a causal relationship cannot be proven easily. In particular, jurists, too, must consider the application of population-based evidence presented by epidemiologists to lawsuits in a forward-looking manner for redressing damages to individuals with diseases; thus, bridging the gap between normative adjudication and scientific judgment to draw a conclusion about a causal relationship.