Breathing Diesel Fumes can Take Your Breath Away

Lung cancer mortality linked with diesel exhaust exposure

(RxWiki News) Nothing very appealing about taking whiffs of truck exhaust. The exposure isn't just unappealing, though. It may be deadly.

Being exposed to heavy diesel exhaust (DE) may increase the risks of dying from lung cancer. That's the latest finding about fumes that were classified as carcinogens in 1989.

"Do whatever you can to avoid breathing diesel exhaust."

The Diesel Exhaust in Miners Study was designed to determine the association between DE and lung cancer mortality. The study was led by Michael D. Attfield, Ph.D., formerly of the National Institute for Occupational Safety and Health, in Morgantown, West Virginia and Debra T. Silverman, Sc.D., of the National Cancer Institute.

Researchers analyzed information about 12,315 workers in eight underground mines. Data was collected from the time diesel equipment was introduced in each mine (1947-1967) though the end of 1997.

Scientists estimated each worker's exposure to respirable elemental carbon (REC), a term used to describe diesel exhaust exposure.

Not surprisingly, lung cancer risks for underground workers were at least a 50% increased, and increased with higher levels of RE exposure. Longer term exposure of elevated REC also increased cancer risks of above ground workers.

Exposure to other workplace chemicals and toxins including silica, asbestos, non-diesel exhaust-related polycyclic aromatic hydrocarbons, respirable dust, and radon, did not impact findings. 

Using the same group of workers, lead study author Silverman and colleagues looked at lung cancer deaths in 198 workers. Increased lung cancer mortality was seen with increasing levels of REC exposure, even after adjusting for smoking, employment and respiratory disease history.

Silverman writes, "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 writes.

These results also may be a warning to entire cities such as Mexico City and nine urban areas of China which have reported diesel exposure levels comparable to those of some underground workers.

"Thus, if the diesel exhaust/lung cancer relation is causal, the public health burden of the carcinogenicity of inhaled diesel exhaust in workers and in populations of urban areas with high levels of diesel exposure may be substantial," Silverman concludes.

Researchers acknowledged some limitations of the study.

Lesley Rushton, Ph.D., of Imperial College in London, in an accompanying editorial suggests that the increased risks might be mitigated through "stringent occupational and particularly environmental standards for DE exposure."

Methods to lessen exposure might include improving ventilation, regular maintenance of vehicles, limiting worker time in vehicles and turning off the engines when not in use.

This study was published online March 5, 2012 by the Journal of the National Cancer Institute.

Review Date: 
March 8, 2012