Workers Health & Safety Centre

Diesel Engine Exhaust Reclassified as Carcinogenic to Humans by IARC

A truck billowing out diesel engine smoke

Diesel engine exhaust has long been considered a significant threat to worker and public health. However, it’s now officially considered a human carcinogen.

Similar to asbestos and silica, diesel engine exhaust is now recognized as a human carcinogen by the International Agency for Research on Cancer (IARC). IARC is part of the United Nation’s World Health Organization (WHO).

The decision to reclassify diesel engine exhaust from a probable human carcinogen (Group 2A) to a definite human carcinogen (Group 1) is the result of compelling scientific evidence, according to a panel of scientific experts convened by IARC. They explained in a June 12, 2012 press release, “Diesel exhaust is a cause of lung cancer and also noted a positive association with an increased risk of bladder cancer.

Doctor Kurt Straif, Head of the IARC Monographs Program, said in this same press release, “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.

Millions of Canadians are exposed to diesel engine exhaust when they breathe. And according to CAREX Canada, more than 800,000 Canadians are occupationally exposed to diesel engine exhaust. Here in Ontario, more than 275,000 workers are exposed including truckers, bus drivers, heavy equipment and farm tractor operators, miners, landscaping labourers and maintenance workers.

Ontario employers are required by law to take every precaution reasonable in the circumstances for the protection of a worker. The Workers Health & Safety Centre has recently updated a diesel exhaust fact sheet highlighting examples of precautions designed to help protect workers and the public. The fact sheet also outlines the numerous additional risks to health posed by diesel exhaust.

All of this information and much more are explored in the WHSC Vehicle Emissions training program.

Want to read the WHSC Vehicle Emissions course descriptor?

Want to read the newly updated WHSC diesel exhaust fact sheet?

Want to read the IARC Diesel Engine Exhaust press release?

Want to know more about exposure estimates from CAREX Canada?

Want to learn more about the full range of WHSC training programs and services? Call Toll Free 1-888-869-7950 and ask to speak to a WHSC Training Services representative.