Household Indoor Concentration Levels of Nitrogen Dioxide (NO2) and Ozone (O3) in Eskisehir, Turkey

Abstract

The concentrations of nitrogen dioxide (NO2) and ozone (O3) were determined at five indoor environments (corridor, living area, bedroom, kitchen, bathroom) of two homes located in different regions of Eskisehir, Turkey. Home 1 is located in the city center and urban residential area and Home 2 is located in a suburban area. In order to determine the indoor and outdoor concentration ratios of the pollutants (I/O), outdoor sampling was also carried out simultaneously with indoor sampling. Sampling studies were performed in one-day periods in four seasons using a passive sampling method. The indoor NO2 concentrations varied between 8.80 and 124.18 µg/m3, while O3 concentrations varied between 4.15 and 22.10 µg/m3. The highest NO2 concentrations were determined in the kitchens both in two homes. This can be due to the intensive cooking activities carried out in the kitchens. The variation in O3 concentrations in the measured indoor environments varied in homes. When the outdoor concentrations were examined, it was seen that NO2 concentrations were higher in Home 1 and O3 concentrations were higher in Home 2 in all seasons. This result is related to the location of the homes. The I/O ratios for NO2 were generally >1 for the kitchens. Moreover, all I/O ratios for NO2 in Home 2 were found >1 in autumn season. The I/O ratios for O3 were found to be <1 in both homes in all seasons. Seasonal variations in the pollutant concentration levels were also observed for indoor environments. Indoor NO2 concentrations, especially in Home 1, and O3 concentrations, especially in Home 2, were higher in spring and summer compared to other seasons. The reason for this is thought to be more active natural ventilation due to the warming of the weather in these seasons.