Debates on Causation in Tobacco Lawsuits

Abstract

With regard to smoking-related lawsuits today, the grounds on which plaintiffs arguing damages due to smoking charge criminal defendants with legal responsibility have developed from the existing responsibility for illegal harmful acts into struggles over a new legal principle since the legislation of the South Korean Product Liability Act. According to this legal principle, tobacco is a defective product, and criminal defendants can be charged with legal responsibility when plaintiffs suffer damages due to tobacco and prove the probability of the occurrence of damage regarding a causal relation between the defects of tobacco and the occurrence of the damage. However, lung cancer, which is a chronic disease, develops only after long-term exposure to smoking and can involve interventions of other factors as well, which complicates the determination of causal relations. Consequently, as in the medical malpractice lawsuits examined above, mitigation of the plaintiffs’ burden of proof can be considered. However, the South Korean Supreme Court, which has ruled in favor of criminal defendants in smoking-related lawsuits filed by the plaintiffs, has not sufficiently accepted epidemiological evidence in proving causal relations. The reasoning is that even when epidemiological correlations are acknowledged in the case of non-specific diseases such as lung cancer, the plaintiffs must prove aspects including the exposure time regarding harmful factors, the degree of their exposures to these factors, the time of disease onset, health status before exposure to the harmful factors, and lifestyles and must thus prove the probability of the causation of non-specific diseases by those factors. In other words, the South Korean Supreme Court has judged that epidemiological evidence fails to be valuable evidence in lawsuits to determine responsibility for the occurrence of damage to individuals because epidemiological research studies populations instead of individuals. Moreover, while negligence can be seen as existing when tobacco companies, manufacturers of harmful products, have failed sufficiently to notify consumers of the harms of tobacco, the Supreme Court has ruled that these companies have appropriately performed their duty of describing potential risks, which in this case consists of what are known as the instruction defects of products.