The International Agency for Research on Cancer ( IARC ) has classified outdoor air pollution as a cancer-causing agent ( carcinogen ). The IARC is part of the World Health Organization, and is one of the primary sources for information on cancer-causing substances for the American Cancer Society and other organizations. In its evaluation, the IARC concluded that outdoor air pollution causes lung cancer and is also linked to an increased risk for bladder cancer.
The IARC has previously classified many components of outdoor air pollution as carcinogens, including diesel engine exhaust, solvents, metals, and dust. But this is the first time it has classified outdoor air pollution – as a whole – as a carcinogen. It also classified another major component of outdoor air pollution – called particulate matter – as a carcinogen on its own.
Particulate matter is a combination of extremely small solid particles and liquid droplets that are found in the air. Particulate matter can include things like dust or smoke, as well as chemicals. The IARC evaluation showed an increasing risk of lung cancer with increasing levels of exposure to outdoor air pollution and particulate matter.
Air pollution is already known to increase risks for other diseases, especially respiratory and heart diseases. Studies show that levels of exposure to air pollution have increased significantly in some parts of the world, mostly in rapidly industrializing countries with large populations. The most recent data from the Global Burden of Disease Project indicate that in 2010, 3.2 million deaths worldwide resulted from air pollution, including 223,000 from lung cancer.
The IARC based its report on a review of more than 1,000 scientific papers from studies on 5 continents. The studies analyzed the cancer risk caused by various pollutants present in outdoor air pollution, especially particulate matter and transportation-related pollution. The findings came from large epidemiologic studies that included millions of people living in Europe, North and South America, and Asia.
According to the IARC, the predominant artificial sources of outdoor air pollution are transportation, stationary power generation, industrial and agricultural emissions, and residential heating and cooking. ( Xagena )
Source: IARC, 2013