Diesel exhaust associated with higher heart attack, stroke r...( ORLANDO Nov. 6 Increased roadway pol...),Health

ORLANDO, Nov. 6 Increased roadway pollution produced by diesel fuel in vehicles is leading to a cascade of conditions that could result in heart attack or stroke, researchers suggested in the report of a small study presented at the American Heart Associations Scientific Sessions 2007.

United Kingdom and Swedish researchers found that diesel exhaust increased clot formation and blood platelet activity in healthy volunteers which could lead to heart attack and stroke.

The study results are closely tied with previous observational and epidemiological studies showing that shortly after exposure to traffic air pollution, individuals are more likely to suffer a heart attack, said Andrew Lucking, M.D., lead author of the study and a cardiology fellow at the University of Edinburgh in the United Kingdom. This study shows that when a person is exposed to relatively high levels of diesel exhaust for a short time, the blood is more likely to clot. This could lead to a blocked vessel resulting in heart attack or stroke.

The double-blind, randomized, cross-over study included 20 healthy men, 21 to 44 years old. They were separately exposed to filtered air (serving as a control) and to diluted diesel exhaust at 300 micrograms per meter cubed (mcg/m3), a level comparable to curbside exposure on a busy street.

Researchers performed the exposures in a specially built diesel exposure chamber. At two hours and at six hours after exposure, researchers allowed a small amount of participants blood to flow through a perfusion chamber. They measured clot formation, coagulation, platelet activation and inflammatory markers after each exposure.

To measure clot formation, researchers used low and high shear rates, recreating flow conditions inside the bodys blood vessels. Compared to filtered air, breathing air with diluted diesel exhaust increased clot formation in the low shear chamber by 24.2 percent and the high shear chamber by 19.1 percent. T
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