Traffic pollution may trigger AMI hours after exposure

TRANSIENT high pollution levels, such as those experienced by drivers in heavy traffic, could trigger a myocardial infarction up to six hours after exposure, research shows.

British researchers linked geographical data on myocardial infarctions with the timing of exposure to pollutants, including particles with diameter less than 10 micrometres (PM10) and nitrogen dioxide (NO2), both associated with traffic pollution.

Among nearly 80,000 patients diagnosed with myocardial infarctions, they found PM10 and NO2 levels were associated with around a 1% increased risk of myocardial infarction per 10 mg/m3 one to six hours after exposure.

However, there was no increased risk of myocardial infarction with any of the pollutants tested for the 72-hour period after exposure, and in fact for ozone and carbon monoxide there was a protective effect.

The effect of NO2 on myocardial