Diesel exhaust has long been classified as a probable carcinogen. But the 20-year study from the National Cancer Institute took a closer look by tracking more than 12,000 workers in certain kinds of mines — facilities that mined for potash, lime and other nonmetals. They breathed varying levels of exhaust from diesel-powered equipment, levels higher than the general population encounters.
The most heavily exposed miners had three times the risk of death from lung cancer compared to workers with the lowest exposures, said the study released Friday by the Journal of the National Cancer Institute.
Even workers with lower exposures had a 50 per cent increased risk, wrote lead author Debra Silverman, an NCI epidemiologist.
"Our findings are important not only for miners but also for the 1.4 million American workers and the 3 million European workers exposed to diesel exhaust, and for urban populations worldwide," Silverman wrote.