LONDON – Diesel fumes cause cancer, the World Health Organization’s cancer agency declared Tuesday, a ruling it said could make exhaust as important a public health threat as secondhand smoke.
The risk of getting cancer from diesel fumes is small, but since so many people breathe in the fumes in some way, the science panel said raising the status of diesel exhaust to carcinogen from “probable carcinogen” was an important shift.
“It’s on the same order of magnitude as passive smoking,” said Kurt Straif, director of the IARC department that evaluates cancer risks. “This could be another big push for countries to clean up exhaust from diesel engines.”
Since so many people are exposed to exhaust, Straif said there could be many cases of lung cancer connected to the contaminant. He said the fumes affected groups including pedestrians on the street, ship passengers and crew, railroad workers, truck drivers, mechanics, miners and people operating heavy machinery.
The new classification followed a weeklong discussion in Lyon, France, by an expert panel organized by the International Agency for Research on Cancer. The panel’s decision stands as the ruling for the IARC, the cancer arm of the World Health Organization.
The last time the agency considered the status of diesel exhaust was in 1989, when it was labeled a “probable” carcinogen. Reclassifying diesel exhaust as carcinogenic puts it into the same category as asbestos, alcohol and ultraviolet radiation.
Experts in Lyon had analyzed published studies, evidence from animals and limited research in humans. One of the biggest studies was published in March by the U.S. National Cancer Institute. That paper analyzed 12,300 miners for several decades starting in 1947. Researchers found that miners heavily exposed to diesel exhaust had a higher risk of dying from lung cancer.
Lobbyists for the diesel industry argued the study wasn’t credible because researchers didn’t have exact data on how much exposure miners got in the early years of the study; they simply asked them to remember what their exposure was like.
Further restrictions on diesel fumes could force the industry to spend more on developing expensive new technology. Diesel engine makers and car companies were quick to point out emissions from trucks and buses have been slashed by more than 95 percent for nitrogen oxides, particulate and sulfur emissions.