23 October 2004

Exposure to traffic may increase the risk of heart attack in susceptible persons, concluded new study published in the October 21 issue of the New England Journal of Medicine.

In the study—authored by Dr. Annette Peters of the GSF National Research Center in Neuherberg, Germany and co-workers—691 heart attack survivors in the Augsburg, Germany area were questioned about their activities during the four day period before their heart attack. It was found that those who were exposed to traffic through such activities as driving, riding or bicycling were three times more likely to suffer a heart attack within one hour after the exposure than those who stayed away from traffic.

The most common source of exposure to traffic was the use of a car. However, there was also an association between time spent on public transportation and the onset of a heart attack one hour later. The authors concluded that traffic could be responsible for 8% of the heart attacks in their survey.

An association between exposure to urban traffic and cardiovascular disease has been suggested in previous studies, which have often linked heart disease to such factors as stress and noise. However, the heart attack risk found in the German study may be associated with pollution, said the study authors, and possibly explained by a heart’s rhythm disturbance triggered by ambient particulate matter.

The study provides another indication that ambient particles, which have been associated with respiratory disease for quite some time, may be in fact interfering not only with lung function, but also with other organs, such as the heart and blood vessels.

The study was partly funded by the US Environmental Protection Agency.

Source: New England Journal of Medicine (Paper abstract)