Pollution characteristics of metal pollutants in PM2.5 and comparison of risk on human health in heating and non-heating seasons in Baoding, China

PM2.5 particles were collected to study the distribution, accumulation and health risk assessment of metal pollutants. The concentrations of 11 kinds of metal elements in PM2.5 during heating period and non-heating period were analyzed. Based on the American health risk assessment model as well as the human exposure parameters in China, the human health risk was assessed. The concentrations of metal components in PM2.5 during the heating period were, in descending order, Pb, Mn, Cr, As, Sb, Se, Ni, Cd, Tl, Hg, and Be, while during the non-heating period, they were basically in the same order, except Cd and Ni, as the concentration of the former was a little higher than that of the latter. The concentrations of As, Cd, Hg, Ni, Se, and Tl were quite different in the heating period and non-heating period. The non-carcinogenic risks caused by metal elements were lower than the minimum acceptance 10(-6) per year during both the heating period and non-heating period. The non-carcinogenic results of a descending order were Pb, Mn, Sb, Tl, Se, and Hg. The carcinogenic risks of a descending order were Cr, As, Cd, Ni, and Be. The risks of As and Cr to children were over 10(-6). Hence, As and Cr should be considered as priorities.