Posted on Oct 12, 2011, 6 a.m.
Just hours after exposure, heavy air pollution may hasten the onset of a heart attack.
While air pollution's biggest health impact results from years or decades of chronic exposure, Krishnan Bhaskaran, from the London School of Hygiene and Tropical Medicine (United Kingdom), and colleagues assessed data from two national databases -- clinical data from the Myocardial Ischemia National Audit Project (MINAP), and air pollution data from the UK National Air Quality Archive. The team reported that heavy air pollution may hasten the onset of a heart attack in the hours after exposure. Revealing that every 10 microgram/m3 increase in small particulate matter and nitrogen dioxide temporarily boosted MI risk by 1.2% and 1.1%, respectively, the increased risks were seen up to six hours after exposure to typical traffic-related pollutants. The researchers posit that air pollution may not actually increase risk of heart attack, but accelerates impending events through a "short-term displacement" effect.
Krishnan Bhaskaran, Shakoor Hajat, Ben Armstrong, Andy Haines, Emily Herrett, Paul Wilkinson, Liam Smeeth. “The effects of hourly differences in air pollution on the risk of myocardial infarction: case crossover analysis of the MINAP database.” BMJ 2011;343; 20 September 2011.