High levels of traffic pollution could increase the risk of heart attack for up to six hours after exposure, according to research published in the British Medical Journal .
Krishnan Bhaskaran, an epidemiologist at the London School of Hygiene and Tropical Medicine, and his colleagues reviewed 79,288 cases of heart attack from 2003 to 2006 and exposure to pollution levels. In addition, they used the British National Air Quality Information Archive to relate it to the levels of specific pollutants in the atmosphere. These include particulate pollutants (PM10), carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2) and ozone (O3). Airborne pollutants and nitrogen dioxide are known traffic-related pollution markers.
Given the transitory nature of the increased risk, scientists speculate that the heart attack would have occurred anyway and was only a few hours early. This is known as the short-term displacement of the effect of pollution. In any case, Bhaskaran recommends avoiding exposure to these gases as much as possible , which previous studies have shown to increase mortality and morbidity.
