Traffic Fumes Increase Heart Attack Risk

Heart attack risk increase during rush hour

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Sitting in heavy traffic may be more than an annoyance. It also appears to make people more susceptible to a heart attack for a six-hour window after inhaling large amounts of fumes.

The temporary risk increase was not found to cause a heart attack, but could be a contributor in hastening one.

"Avoid heavy traffic pollution when possible."

Krishnan Bhaskaran, study leader and a lecturer in statistical epidemiology at the London School of Hygiene and Tropical Medicine, found that repeated exposure to high levels of car exhaust also could shorten life expectancy in addition to creating a temporary heightened heart attack risk.

Researchers reviewed data on nearly 80,000 patients who had suffered myocardial infarction, a type of heart attack in England and Wales between 2003 and 2006. They also studied air pollution data, plotting hourly measurements of air pollution including ozone and nitrogen dioxide. Hourly air pollution levels were then compared against the onset of heart attack symptoms.

Higher levels of pollution were found to be linked to an onset of a heart attack within six hours of exposure to traffic fumes. Researchers suggested pollution could make a heart attack that would have happened anyway occur sooner, but the pollution alone would not cause a heart attack.

Despite that, chronic exposure to traffic exhaust was found to be hazardous, suggesting that individuals should do their best to avoid chronically exposing themselves to heavy traffic fumes.

Other studies have shown that traffic pollution can thicken blood and make it more likely to clot, which can increase the risk of a heart attack. After the six hour period, the risk returned to normal.

The study was published Sept. 21 in the British Medical Journal.

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Review Date: 
September 21, 2011
Last Updated:
September 22, 2011