Traffic-generated air pollution and myocardial infarction.

Area of Science:

• Environmental Health
• Cardiovascular Epidemiology
• Toxicology

Background:

• Long-term air pollution exposure is a known risk factor for cardiovascular mortality.
• Data on air pollution's impact on nonfatal coronary events and incidence remain limited.
• Traffic-related air pollution is a significant environmental concern in urban areas.

Purpose of the Study:

• To investigate the association between long-term residential exposure to traffic-generated air pollution and the risk of myocardial infarction.
• To differentiate the risks for fatal versus nonfatal myocardial infarction.

Main Methods:

• A case-control study design was used, including 24,347 myocardial infarction cases and 276,926 population controls in Stockholm County (1985-1996).
• Individual socioeconomic data and residential addresses were linked to population censuses.
• Annual air pollution exposure, specifically nitrogen dioxide, was estimated using dispersion modeling at individual home addresses.

Main Results:

• A 5-year average exposure to nitrogen dioxide (31 microg/m) was associated with a 23% increased odds of fatal myocardial infarction (OR=1.23, 95% CI=1.15-1.32).
• The association with fatal events was stronger in individuals with stable residential addresses, suggesting reduced exposure misclassification.
• No significant increased risk was observed for nonfatal myocardial infarction (ORs 0.94-0.98).

Conclusions:

• Long-term exposure to traffic-generated air pollution, particularly nitrogen dioxide, is significantly associated with fatal myocardial infarction.
• The study did not find a link between traffic air pollution exposure and nonfatal myocardial infarction.
• These findings underscore the critical impact of air quality on severe cardiovascular outcomes.