The Main Study of the Alberta Oil Sands Community Exposure and Health Effects Assessment Program had three main objectives: 1. Describe the population and personal distribution of exposure to airborne chemicals and particulates: • estimate the population distribution of selected airborne chemicals and particulates; • estimate the seasonal variation of exposure and; • characterize the personal variation of exposure as a function of individual activity patterns. 2. Quantify the relative contribution of various exposure sources and pathways to airborne chemicals: • quantify the relative contribution of outdoor and indoor air to the total exposure. 3. Describe associations between exposure to airborne chemicals and human health effects: • analyze occurrence relationships between selected exposures, biomarkers, and health outcomes.