Wintertime indoor air levels of PM 10, PM 2.5 and PM 1 at public places and their contributions to TSP

Abstract

From 26 October 2002 to 8 March 2003, particulate matter (PM) concentrations (total suspended particles [TSP], PM 10, PM 2.5 and PM 1) were measured at 49 public places representing different environments in the urban area of Beijing. The objectives of this study were (1) to characterize the indoor PM concentrations in public places, (2) to evaluate the potential indoor sources and (3) to investigate the contribution of PM 10 to TSP and the contributions of PM 2.5 and PM 1 to PM 10. Additionally, The indoor and outdoor particle concentrations in the same type of indoor environment were employed to investigate the I/O level, and comparison was made between I/O levels in different types of indoor environment. Construction activities and traffic condition were the major outdoor sources to influence the indoor particle levels. The contribution of PM 10 to TSP was even up to 68.8%, while the contributions of PM 2.5 and PM 1 to PM 10 were not as much as that of PM 10 to TSP.