A population-based case-referent study of myocardial infarction and occupational exposure to motor exhaust, other combustion products, organic solvents, lead, and dynamite

This case referent study investigated the risk of myocardial infarction fro m occupational exposure to motor exhaust, other combustion products, organi c solvents, lead, and dynamite. We identified first-time, nonfatal myocardi al infarctions among men and women 45-70 years of age in Stockholm County f rom 1992 through 1994. We selected referent subjects from the population to match the demographic characteristics of the cases. A lifetime history of occupations was obtained by questionnaire. The response rate was 81% for th e cases and 74% for the referents, with 1,335 cases and 1,658 referents inc luded in the study. An occupational hygienist assessed occupational exposur es, coding the intensity and probability of exposure for each subject. We a djusted relative risk estimates for tobacco smoking, alcohol drinking, hype rtension, diabetes mellitus, overweight, and physical inactivity at leisure time. The relative risk of myocardial infarction was 2.11 (95% confidence interval = 1.23-3.60) among those who were highly exposed and 1.42 (95% con fidence interval = 1.05-1.92) among those who were intermediately exposed t o combustion products from organic material. We observed an exposure-respon se pattern, in terms of both maximum exposure intensity and cumulative dose . Exposure to dynamite and organic solvents was possibly associated with an increased risk. The other exposures were not consistently associated with myocardial infarction.