Source apportionment for indoor PM2.5 and elemental concentrations using by a positive matrix factorization and an instrumental neutron activation analysis

Airborne particulate matters, especially the PM2.5 (aerodynamic equivalent diameter, AED, less than 2.5 μm) fraction has been important. This is because of their potential for deposition on to the human respiratory system being accompanied by many harmful trace metals (such as As, Cd, Cr, Cu, Mn, Pb, Se, and Zn). The indoor air quality has become a great concern since late 1980s, because the population spends a majority of their time in various indoor environments. The indoor particulate matter may be influenced from outdoor environment and indoor sources such as environmental tobacco smoke (ETS), combustion devices, cooking, etc. In this study, we undertake the measurements of about 26 elements using instrumental neutron activation analysis (INAA). Based on our measurement data, we characterize concentration status and mutual relationship between indoor and adjacent outdoor air quality. Next, sources at indoor/outdoor environment were identified and the contributions of each source were quantified by positive matrix factorization (PMF)