Diesel Exhaust Linked to Greater Lung Cancer Risk: WHO Study

Exposure to diesel exhaust from trucks, trains and other diesel engines pose a risk of cancer for humans, according to the World Health Organization (WHO). 

WHO’s International Agency for Research on Cancer (IARC) published an announcement on June 12, indicating that the group has classified diesel engine exhaust as carcinogenic to humans (PDF). This places the gas fumes in the same category as exposure to radiation, cigarettes and other known cancer causing products.

The decision came after a week-long meeting involving international experts, who determined that diesel exhaust exposure increases the risk of lung cancer. There is also evidence of an association with bladder cancer.

Since 1988, the IARC has considered diesel fumes to be a probable carcinogen. The group decided to revisit the classification after a study published in March by the U.S. National Cancer Institute found that diesel exhaust exposure was linked to lung cancer deaths among U.S. miners.

“Large populations are exposed to diesel exhaust in everyday life, whether through their occupation or through the ambient air,” IARC reported. “People are exposed not only to motor vehicle exhausts but also to exhausts from other diesel engines, including from other modes of transport (e.g. diesel trains and ships) and from power generators.”

The new classification and the scientific evidence the agency gathered will make it politically easier for governments to place new restrictions and regulations on diesel exhaust. However, the agency left it up to individual governments and future studies to determine what level of diesel exhaust exposure was a threat to human health.

The IARC working group that tackled the issue decided not to change the categorization of gasoline exhaust from its current rating as possibly carcinogenic to humans, which has been the classification since 1989.

A summary of the IARC diesel exhaust evaluation is slated to be published tomorrow in the online edition of The Lancet Oncology.