October 30, 2011

Study Finds Link Between Air Pollution, Lung Cancer

Nonsmokers who live in locations with high levels of air pollution are approximately 20% more likely to die as a result of lung cancer than those who live in clean-air areas, a team of researchers claim in a new study.

In their research, Michelle C. Turner, Daniel Krewski, C. Arden Pope III, and Susan M. Gapstur of the University of Ottawa, Yue Chen of Brigham Young University (BYU), and Michael J. Thun of the American Cancer Society's Epidemiology Research Program followed more than 188, 000 non-smokers for 26 years, Kerry Grens of Reuters reported on Friday.

Subjects represented all 50 states, as well as Puerto Rico, and based on their zip codes, Turner and her colleagues estimated the amount of air pollution levels they would have been exposed to ("measured in units of micrograms of particles per cubic meter of air," according to Grens).

"Pollution levels in different locations ranged from a low of about six units to a high of 38," with an overall average level of 17, the Reuters reporter said. "After the team took into account other cancer risk factors, such as second-hand smoke and radon exposure, they found that for every 10 extra units of air pollution exposure, a person's risk of lung cancer rose by 15 to 27 percent."

A total of 1,100 people died as a result of the disease during the course of the study, and the decrease was said to be "small" when compared to the "20-fold" increase associated with cigarette smoking, Grens said.

Furthermore, Turner, of the university's McLaughlin Centre for Population Health Risk Assessment, told Reuters Health that their findings did not prove that pollution caused cancer, but that there was "lots of evidence that exposure to fine particles increases cardiopulmonary mortality."

"The present findings strengthen the evidence that ambient concentrations of PM2.5 (ambient fine particulate matter) measured in recent decades are associated with small but measurable increases in lung cancer mortality," the researchers wrote in their study, which was published online in the American Journal of Respiratory and Critical Care Medicine on October 6.


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