The heavy metals in indoor and outdoor PM2.5 from coal-fired and non-coal-fired area

Abstract

To compare the pollution characteristics and sources of heavy metal in indoor and outdoor PM2.5 from coal-fired and non-coal-fired area in winter of Qian'an City, PM2.5 samples were collected in January 2016. The methods of EF and PCA were used to discuss the sources of heavy metal in PM2.5. The results showed that the average concentration indoor and outdoor PM2.5 were 128.45 and 46.27 μg/m3) in coal-fired area, 66.64 and 29.82 μg/m3 in non-coal-fired area. The ratio of I/O was more than one for Cr, Cu, Zn, Cd and Pb, and lower one for Ni indoor and outdoor environment. Indoor sources were more contributed to Cr in coal-fired area. About 4% of Ni, 40% Cu, 64% Zn, 62% Cd, 54% Pb entered indoor from outdoor for coal-fired area. The 11% of Ni entered indoor from outdoor for non-coal-fired area. EF and PCA method indicated that coal combustion and metal smelting was main contributor for indoor PM2.5, however metal smelting was main sources for outdoor PM2.5. The present study suggested that the central heating and industry reduction would effectively improve indoor air quality in rural-urban fringe zone.