[Causal link in the assessment of the relationship between neoplastic diseases and occupational and environmental exposure in the judicial field].

IARC evaluations of the carcinogenic risk to humans, although based on epidemiological and experimental studies, derive their value from the consensus among committee members on a decision based on the current status of knowledge, not from the studies themselves, nor from their summary evaluation. A judiciary setting, based on the opinion of an individual expert, or on the evaluation of the most updated state of the knowledge by a group of experts selected in non scientific settings, or even worse on the evaluation of a specific case with ad hoc epidemiological studies, cannot confute such decisions. Therefore, causal links already defined within the scientific community, such as between exposures in the IARC category 1 and specific cancer sites, should be accepted also in legal trials to establish individual responsibility in case of excess exposures for the general and/or the working population resulting from violation or omission of preventive duties, when those diseases follow such excess exposures. If no violation or omission occurred, a civil responsibility has to be defined when either a disease with established link with the given exposure occurs, or a disease for which no such a level of consensus exists in the scientific community, but for which the legal trial has reached a positive decision. In such instances, if omissions or law violations occurred, the legal trial carries the burden of establishing a causal link between such omissions and violations and the damage for the individual worker or citizen.