World Health Organization confirms air pollution as cause of lung cancer

(http://seattletimes.com) Air pollution has long been suspected as a contributor to lung cancer, but its role as a carcinogen has only just recently been confirmed. On Thursday, the International Agency for Research on Cancer, the cancer agency of the World Health Organization, declared that air pollution is a carcinogen comparable to other known dangers, including asbestos, tobacco and ultraviolet radiation.

"The air most people breathe has become polluted with a complicated mixture of cancer-causing substances," said Kurt Straif, head of the IARC department that evaluates carcinogens. According to The Seattle Times, "he said the agency now considers pollution to be 'the most important environmental carcinogen,' ahead of second-hand cigarette and cigar smoke."

The IARC previously declared components of air pollution, such as diesel exhaust, to cause cancer, but this is the first time that air pollution in general has been deemed carcinogenic. Individual risk from air pollution is low, but sources of exposure are widespread and often unavoidable.

"Air pollution is a complex mixture that includes gases and particulate matter, and [the] IARC said one of its primary risks is the fine particles that can be deposited deep in the lungs of people," The Seattle Times reported.

To reach their conclusion, the IARC analyzed over 1,000 studies and determined that there was enough evidence that exposure to air pollution causes lung cancer to classify it as a carcinogen.