This report provides an overview of the Alberta Oil Sands Community Exposure and Health Effects Assessment Program Main Study. The report describes the population and personal distribution of exposure to airborne chemicals and particulates in the city of Fort McMurray. Using a personal exposure model, the relative contribution of various exposure sources and pathways to airborne chemicals is estimated and associations between exposure to airborne chemicals and human health effects are described. The data used for the analysis was collected over an 18-month period (June 1997 to November 1998), using volunteers from the city of Fort McMurray. A small sample of volunteers was also recruited from the city of Lethbridge that served as a control community for the Fort McMurray sample. Data from the two communities was evaluated and, where applicable, additional comparisons were made to the scientific literature. The study collected a variety of measures for each participant, including personal, indoor, and outdoor levels of selected contaminants (sulfur dioxide, nitrogen dioxide, ozone, a group of volatile organic compounds, and particulate matter), measures of other sources of exposure, diet and health behaviors, and selected health outcomes.