Indoor and outdoor SO₂ in a community near oil sand extraction and production facilities in northern Alberta

A baseline study measuring indoor and outdoor sulfur dioxide (SO₂) levels was undertaken in a small native community (Fort McKay) in northern Alberta. The objective was to assess whether proximity of numerous oil sand operations affected air quality in the community. A passive sampling device was deployed for 96 h durations at 30 randomly selected homes over a 6 week period such that 75% of homes were sampled during weekdays and 25% during weekends. The common living area of each home (kitchen or family room) was sampled indoors. Outdoor passive samplers were attached to a sampling stand under a shelter in the yard. Indoor SO₂ levels were all less than a method detection limit of 1.3 µg/m³ (n = 30). The median outdoor level was 1.7 µg/m³ (n = 28, range 1.3 to 3.7 µg/m³, 70% > method detection level). Results of testing to determine accuracy and precision of the monitors showed both measures to be within 35% based on a 96 h average measurement. Overall, these levels are considered very low and consistent with levels observed elsewhere in Alberta. Key words: sulfur dioxide, passive sampling, indoor and outdoor air.