The AHSMOG Study began in 1977 as a substudy consisting of 6,338 individuals who were also members of the larger parent Adventist Health Study (AHS-1). AHS-1 had already enrolled over 34,000 non-smoking non-Hispanic white California adults and it was believed that this population provided a unique opportunity for also investigating the health effects of long-term exposure to ambient air pollutants with very little confounding (distortion) by active tobacco exposure. However, Seventh-day Adventists' contact with ambient air pollution varies greatly by virtue of their choice of residence and occupation. This variability in pollution exposure makes possible the evaluation of the relationship between exposure and health effects with minimal distortion by tobacco smoke.
Individuals from three major geographic areas [Southcoast air basin (Los Angeles and eastward), San Diego metropolitan district, and the San Francisco metropolitan district, and a 13% random sample from the rest of California] were invited to complete National Heart, Lung and Blood Institute respiratory symptoms questionnaires in 1977, 1987, 1992 and 2000. Since 1977 the cohort has been followed and monitored for newly diagnosed malignant neoplasms, coronary heart disease, and all-cause mortality. In addition, computer algorithms were applied to the respiratory symptoms questions to classify individuals as having none, possible, or definite symptoms for each of chronic bronchitis, asthma, emphysema.
Funding for acquisition of data for the AHSMOG study has come from: the National Cancer Institute, the National Heart, Lung and Blood Institute, the National Institute for Environmental Health Sciences, the U.S. Environmental Protection Agency, and the American Cancer Society.