New Delhi. Inhaling diesel exhaust fumes causes changes in the body that may make people more prone to heart attack or stroke, said Dr. KK Aggarwal, President, Heart Care Foundation of India.

In a study European scientists have shown that blood clots are more likely to form in otherwise healthy people exposed to relatively high amounts of diesel engine exhaust fumes for a short time. This could cause a blocked vessel, heart attack or stroke.

Diesel engines spew many times more fine pollutant particles than gasoline engines. People with heart and artery disease should stay away from traffic congestion to avoid the effects of this pollution. The study involved 20 healthy men, aged 21 to 44 years. They breathed filtered air and also diluted diesel exhaust at a level approximating curbside exposure on a busy road.

Compared to breathing filtered air, breathing air with the diesel exhaust fumes increased clot formation by roughly 20 - 25 percent in the hours after exposure. The researchers also found an increase in platelet activation in the blood. Platelets play a major role in clotting.

The same group reported in the New England Journal of Medicine that heart attack victims showed clear differences when breathing diesel fumes. They found that the hearts of heart attack survivors were far more likely to be starved of oxygen when exercising while breathing in such fumes than when exercising in clear air.