Pollution characteristics and chronic health risk assessment of metals and metalloids in ambient PM2.5 in Licheng District, Jinan, China

PM2.5 samples were collected at the Wangsheren primary school site in Licheng District of Jinan, China, during 2016. Eleven metals and metalloids including Al, As, Be, Cd, Cr, Hg, Mn, Ni, Pb, Sb and Se in PM2.5 were measured by inductively coupled plasma-mass spectroscopy. The annual average mass concentration of PM2.5 was found to be 88.7 mu g m(-3). The highest PM2.5 concentrations were obtained during the heating seasons of winter and spring. The concentrations of metals and metalloids in PM2.5 were in a descending order of Al, Pb, Mn, As, Se, Cr, Sb, Ni, Cd, Hg and Be. The enrichment factors showed that Pb, Mn, As, Se, Cr, Sb, Ni, Cd, Hg originated from anthropogenic sources. Factor analysis indicated that the main sources of the metals were coal combustion dust, soil dust, metallurgical industry, brake abrasion of vehicles and other mixed sources. Coal combustion dust was the primary source of metal pollution in PM2.5. Non-carcinogenic risks associated with exposure through the respiratory system were between 6.30 x 10(-4) and 7.62 x 10(-1), which were lower than the safe limit (1). The carcinogenic risks of Cr, As and Cd were 3.17 x 10(-5), 1.52 x 10(-5), 2.22 x 10(-6), respectively, which were higher than the precautionary criterion (10(-6)/year). This study indicates that the air pollution of PM2.5 is of public health concern in Licheng District of Jinan, particularly related to potential carcinogenic metals of As, Cr and Cd. Intervention action is needed to reduce the emission sources of these elements, especially coal combustion in winter heating season.