While there was no association between people's exposure to various pollutants over a 30year period and overall heart attack risk, such exposure did appear to be associated with a greater risk of fatal heart attack, especially those occurring outside hospitals, Mats Rosenlund of the Stockholm County Council reports.

Long-term pollution exposure could contribute to heart attack risk by causing hardening of the coronary arteries and altering heart function.

In a study of 1,397 people, researchers found that people who had lived in pollution "hot spots" with particularly dirty air had a 23% increased risk of heart attack, and a 40% increased risk of fatal heart attack.