Exposure to urban nitrogen dioxide pollution and the risk of myocardial infarction

Scand J Work Environ Health. 2004 Aug;30(4):293-8. doi: 10.5271/sjweh.797.


Objectives: This study attempted to determine whether long-term exposure to nitrogen dioxide (NO2), an indicator of motor vehicle exhaust, increases the risk of myocardial infarction (MI).

Methods: A population-based case-control study was conducted among men aged 25-64 years and residing in Kaunas, Lithuania. The study included all cases of first-time myocardial infarction in 1997-2000. Interviews with patients treated in hospitals elicited information on smoking and other risk factors, including residential histories. A high response rate (77.4%) resulted in 448 cases and 1777 controls. Nitrogen dioxide (NO2) was selected for analysis as an indicator of traffic-related air pollution. The annual air pollution levels were estimated for the residential districts; thereafter the data were linked to the home addresses of the cases and controls.

Results: After adjustment for age, education, smoking, blood pressure, body mass index, marital status, and psychological stress, the risk of myocardial infarction was higher for the men exposed to medium [odds ratio (OR) 1.43, 95% confidence interval (95% CI) 1.04-1.96] and high (OR 1.43, 95% CI 1.07-1.92) NO2 levels. The data suggested a stronger association among 55- to 64-year-old men. The risk of myocardial infarction increased by 17% among the 25- to 64-year-old men (OR 1.17, 95% CI 1.01-1.35) and by 34% among those aged 55-64 years (OR 1.34, 95% CI 1.08-1.67) from the first to the third tertile of NO2 exposure.

Conclusions: The results indicate that urban NO2 pollution may increase the risk of myocardial infarction and that vehicle emissions may be of particular importance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Air Pollutants / toxicity*
  • Case-Control Studies
  • Confounding Factors, Epidemiologic
  • Humans
  • Lithuania / epidemiology
  • Middle Aged
  • Myocardial Infarction / epidemiology*
  • Myocardial Infarction / etiology
  • Nitrogen Dioxide / toxicity*
  • Risk Factors
  • Urban Population*


  • Air Pollutants
  • Nitrogen Dioxide