IARC reclassifies diesel engine exhaust as carcinogenic

The International Agency for Research on Cancer (IARC), which is part of the World Health Organization (WHO), has classified diesel engine exhaust as carcinogenic to humans (Group 1), based on sufficient evidence that exposure is associated with an increased risk for lung cancer. In 1988, IARC classified diesel exhaust as probably carcinogenic to humans (Group 2A). An Advisory Group which reviews and recommends future priorities for the IARC Monographs Program had recommended diesel exhaust as a high priority for re-evaluation since 1998. Christopher Portier, chairman of the IARC working Group, stated that “The scientific evidence was compelling and the Working Group’s conclusion was unanimous: diesel engine exhaust causes lung cancer in humans.” Portier continued: “Given the additional health impacts from diesel particulates, exposure to this mixture of chemicals should be reduced worldwide.” Kurt Straif, head of the IARC Monographs Program, indicated that “The main studies that led to this conclusion were in highly exposed workers. However, we have learned from other carcinogens, such as radon, that initial studies showing a risk in heavily exposed occupational groups were followed by positive findings for the general population. Therefore actions to reduce exposures should encompass workers and the general population.”