April, 2002

Maybe the expression “smokes like a chimney” should be expanded to include “smokes like a motor vehicle.” Though perhaps not in those words, this part of the conclusion reached in a recent study published in the Journal of the American Medical Association. The article, Lung Cancer, Cardiopulmonary Mortality, and Long-term Exposure to Fine Particulate Air Pollution, found that traffic fumes and urban pollution significantly increase the risks of dying from lung cancer and heart disease.

The authors studied half a million adults in the U.S. from 1982 to 1998 in one of the most detailed such studies ever done. They were trying to assess the relationship between long-term exposure to air pollution and lung cancer and heart disease. They found that exposure to pollution’s small particulates may be as bad for your health as exposure to second-hand smoke. Specifically, their conclusion stated that “long-term exposure to combustion-related fine particulate air pollution is an important environmental risk factor for cardiopulmonary and lung cancer mortality.”

Particulates? Our air contains minute particles that we inhale as we breathe. These particulates are suspended in the air and may be comprised of various chemical and physical properties. They are usually identified as PM10 meaning that they are less than 10 microns in diameter — one micron is a millionth of a meter. Particulates not only come from vehicle exhaust, but also from slash burning and other sources.

The greatest concern from PM10 arises from the ability of fine particulates to bypass the body’s natural filtering system to threaten the respiratory tract and pose significant health threats. The smallest particles can lodge in the deepest and most sensitive areas of the lungs. Particles also enter the bloodstream and because blood is carried to all the organs, toxins can thus be spread throughout the body.

Short term exposure to PM10 can cause coughing and minor throat irritation while prolonged exposure can lead to increased bronchial aggravation and higher risk of cancer. Exposure can also aggravate respiratory illnesses such as bronchitis, asthma and emphysema.

Emissions from vehicle that burn fossil fuels include a long list of dangerous compounds: suspended particles including PM10, carbon monoxide, nitrogen dioxide, sulphur dioxide, benzene, formaldehyde and many more. The effects on the body of these substances can be life-threatening. Benzene, for example, is linked to the development of leukemia and lymphoma. It has an effect on bone marrow and impairs the maturation and work of blood cells. Carbon monoxide, CO, arises from incomplete burning of carbon fuels. It binds to blood cells much more effectively than oxygen and is similar to suffocation. CO has also been known to aggravate cardiovascular disease in humans.

Air pollution is the source of many harmful materials that enter the bloodstream through the nose, mouth, skin and digestive tract. Judging from this research, and from simple common sense, it would seem that improving the quality of the air we breathe should be an important goal in our communities. Check out the Sunshine Coast Clean Air Society’s website at www.toffan.com/clear for local information.

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Call-out: “The greatest concern from PM10 arises from the ability of fine particulates to bypass the body’s natural filtering system to threaten the respiratory tract and pose significant health threats.”