Most of the data available for particulate is especially for outdoors. Most of the people spend their time indoors, where exposure to majority air pollution is quite different from that of outdoors. Deterioration of indoor air quality with income growth made many feel concerned about the issue of the pollution-income growth relationship. The possible role of socioeconomic status appears of particular interest, especially after the findings that emerged a chronic health effects of indoor air pollution. It is well known fact that persons of lower income group have generally poorer health than...