Getting hit by a car may not be the only health risk bicyclists should worry about -- cycling in heavy traffic could also pose hidden dangers to their hearts, new research shows.
Canadian researchers found that bicycling in a highly trafficked area ups the risk of heart irregularities in the following hours, according to the small new study published in the journal Environmental Health Perspectives.
The researchers found that even short-term exposure to air pollutants spewed from behind cars and trucks raises the risk of these heart irregularities, which are linked with an increased risk of heart attack, Environmental Health News reported.
Researchers recruited 42 non-smoking cyclists for the study, and had them wear heart monitors while they bicycled for one hour on both low- and high-traffic roads last summer. Their bikes also had instruments that gauged the level of pollution in the air while they biked.
The study comes on the heels of research published earlier this year in the journal The Lancet, which showed that air pollution triggers more heart attacks than cocaine.
However, the benefits of cycling may still outweigh the risks, as long as bicyclists try to avoid heavily trafficked areas. One Dutch study published last year in the journal Environmental Health Perspectives shows that health benefits of cycling are nine times greater -- if not more -- than the potential harms that could come from air pollution or a fatal accident, USA Today reported.
In May of this year, the American Lung Association (ALA) released their annual report, State of the Air (SOTA) 2011, highlighting which cities are the cleanest for ozone pollution, short-term particle pollution, and year-long particle pollution.
Here are the 10 cleanest cities according to the list:
