Motoring Your Way to a Stroke

Stroke risk increased by air pollution exposure

(RxWiki News) Sitting in afternoon gridlock doesn't do any favors for your heart. New research suggests that traffic-related air pollution increases the risk of an ischemic stroke.

Previous research also has suggested air pollution may negatively affect the heart. A September 2011 study published in the British Medical Journal suggested that traffic fumes appear to increase the risk of heart attack.

"Avoid heavy air pollution when possible."

Gregory Wellenius, a lead study author from Brown University, found that patients are at an increased risk of stroke even after short-term exposure to fine particle matter that is below current U.S. National Ambient Air Quality Standards.

During the study researchers reviewed the medical records of 1705 Boston area patients hospitalized with an ischemic stroke that had been confirmed by a neurologist between April 1999, and October 2008. They gathered data about the onset of symptoms and clinical characteristics.

They also measured fine particulate matter concentrations at a central monitoring station, and compared onset of stroke with fine particle matter levels in the hours and days before each patient's stroke.

Investigators discovered that following moderate exposure to air pollution, defined by the Environmental Protection Agency as between 15 and 40 micrograms per cubic meter of air, for a 24-hour period the risk of stroke was significantly increased. This was as compared to to good air quality, defined as 15 micrograms or lower.

This amounted to a 34 percent increased stroke risk following 24 hours of exposure to moderate air pollution. The risk of stroke as a result of traffic pollution was found to be the highest within 12 to 14 hours of exposure.

The study was recently published in the Archives of Internal Medicine.