Newly released studies by the National Cancer Institute (NCI) showing high cancer risks from heavy exposure to diesel exhaust could provide the Environmental Protection Agency with the data it has long been seeking to quantify the substance's cancer risks and update a 2002 risk assessment that classified the substance as a "likely" carcinogen, sources say. The studies are included in an epidemiological study of miners exposed to diesel exhaust, in which NIOSH also participated. But one agency source says that even if EPA were to strengthen its risk assessment of diesel exhaust, it may not have
December 29, 2025