Determination of the personal, indoor and outdoor exposure levels of inorganic gaseous pollutants in different microenvironments in an industrial city

We measured SO 2 , NO 2 and O 3 concentrations during the summer and winter in Kocaeli, Turkey. The sampling was carried out indoors and outdoors at homes, schools and offices. Personal samplers were also used to determine personal exposures to these pollutants. High NO 2 and SO 2 concentrations were observed in outdoor samples collected close to locations characterized by heavy urban traffic. Concentrations of O 3 , on the other hand, were higher in rural areas around the city due to ozone distillation. For both sampling periods, the concentrations of outdoor SO 2 and O 3 were higher than for indoor and personal samples; however, the NO 2 concentrations were higher in indoor and personal samples, indicating that outdoor sources significantly contribute to indoor SO 2 and O 3 levels and that indoor NO 2 concentrations are primarily modulated by sources within buildings. Seasonal variations in pollutant concentrations showed statistically significant differences. Indoor and outdoor concentrations of NO 2 and SO 2 measured in the winter were higher than the levels measured in the summer; O 3 concentrations, on the other hand, exhibited the opposite trend. Active-to-passive concentration ratios for NO 2 , SO 2 and O 3 were 0.99, 1.08 and 1.16, respectively; the corresponding outdoor ratios were 0.95, 0.99 and 1.00.