Effects of socioeconomic factors and human activities on children's PM10 exposure in inner-city households in Korea

In this study, we investigated how socioeconomic factors contributed to airborne PM10 concentrations in living rooms and children's bedrooms in 50 homes in Korea from July to September 2008. PM10 was measured with the personal environmental monitor, and both a questionnaire and time activity diary were used to acquire data on socioeconomic factors and various human activities (i.e., cooking, cleaning, and smoking). Analysis of variance and general linear model were used to identify the effects of socioeconomic and behavioral factors on PM10 concentrations. Mean PM10 concentrations in living rooms and children's rooms were 45.3 +/- A 33.3 mu g/m(3) and 45.9 +/- A 21.0 mu g/m(3), respectively, whereas outdoor PM10 concentrations were 50.0 +/- A 19.8 mu g/m(3). Significant relationships were found between concentrations in children's rooms and living rooms, and also between indoor and outdoor concentrations. PM10 concentrations in children's rooms varied significantly by region, parental education, floor of residence, and average monthly household expenses. Concentrations in living rooms varied significantly by the number of children. This implies that lower socioeconomic status can contribute to higher indoor PM10 concentrations. Indoor PM10 concentrations in households with cleaning, cooking, and smoking were higher than in homes without these activities. General linear model showed that the effects of socioeconomic factors on PM10 concentrations were significant in the following order: region (the increment in estimate beta = 24.16), parental education (beta = -18.84), type of housing (beta = -16.97; p < 0.01), and number of children (beta = 19.12; p < 0.05). We found that indoor PM10 concentrations were affected by socioeconomic factors rather than human behavioral activities. In determining the environmental policy for indoor air quality, it is important to consider various socioeconomic factors of subjects.