PM2.5-bound PAHs in Chinese typical non-ferrous smelting area: appointment and risk assessment associated with specific industrial and biomass sources

Abstract

The non-ferrous smelting industry (NSI) is a key source of atmospheric organic compounds, leading the serious impacts on the surrounding environment and the health of residents over industrial concentration areas. In this study, nine sampling sites were arranged in the NSI aggregation area for seasonal monitoring of PM_2.5-bound PAHs. Our results revealed that total concentration of PM_2.5-bound PAHs was 10.9 ± 4.70 ng/m³. These values reached 49.1 ng/m³ near the NSI, which were 2.8–4.2 times greater than the concentration of the background sample. Seasonal vary caused by sources and meteorology resulted in an average concentration in winter (16.2 ± 2.08 ng/m³) that was 2.6 times higher than that in summer. Based on appointment of specific sources, NSI sources account for 23.5 %–28.5 % of PAHs and biomass burning (BB) contributes significantly to PAHs, up to 28.9 % in spring. The long-range transportation of BB smoke in Southeast Asia is considered the major reason, combined with trajectories and fire spots. Risk assessment showed vehicle and NSI emissions accounted for over 71.1 % of the cancer risk from PM_2.5-bound PAHs exposure. Residents have a higher cancer risk in winter, and the incremental lifetime carcinogenic risk values of adults around the NSI exceed the threshold value (10⁻⁶). The results indicate that residents living near NSI areas face higher health risks, and suggest controlling and managing PAHs emissions related to the NSI.