Field study on indoor air quality of urban apartments in severe cold region in China

The results showed that the indoor PM2.5 and PM10 during the space heating period, especially the haze weather period caused by heavy smog, were polluted seriously. Good linear relationships between indoor and outdoor concentrations of PM were identified in the condition of terrible outdoor air quality. In contrast, the concentrations of HCHO, CO, CO2, NOX and SO2 approximately satisfied the requirements of national standard unless the serious haze weather occurred. According to the subjective surveys, occupants could evaluate the indoor ventilation correctly, but the indoor air quality was always overestimated. Moreover, the factor of illness history of the occupants had an obvious influence on the evaluation of indoor air quality. Furthermore, cooking increased the indoor concentrations of HCHO, CO and TVOC significantly, and the indoor air quality in newly-decorated urban apartments was heavily polluted by HCHO, NH3 and TVOC.