Diesel fumes cause cancer, the World Health Organization's cancer agency declared Tuesday, a ruling it says 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 says 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," says 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 says there could be many cases of lung cancer connected to the contaminant. He says the fumes affected groups including pedestrians on the street, ship passengers and crew, railroad workers, truck drivers, mechanics, miners and people operating heavy machinery.