Health Risk Ranking Assessment of Human Exposure to Multiple Air Pollutants Emitted from Municipal Solid Waste Incineration in China

摘要

Municipal Solid Waste Incineration (MSWI) has developed rapidly with doubled increase in China during 2010-2015. However, risk level of MSWI as well as its spatial distribution were still unknown. A systematic risk identification and ranking assessment is essential to improve effectiveness and pertinence of risk management. In this study, we developed a health risk ranking framework and applied it to assess the MSWI related risk across China. Firstly, a bottom-up multiple-pollutant emission inventory was calculated based on detailed information of 222 MSWIs in mainland China and localized emission factors from literature investigation. Then a Gaussian Plume Model was used to simulate the dispersion of pollutants emitted by each MSWI, considering the perennial dominant wind direction and mean wind speed. Finally, spatialized and population-weighted Hazard Index (HI) and Relative Risk (RR) were calculated to evaluate both non-carcinogenic and carcinogenic health risks caused by individual respiratory exposure from heavy metals and PCDD/Fs. Results show that, in 2015, 59651.6 t of NOx, 20072.2 t of SO_2, 13215.3 t of CO, 7240.0 t of HCl, 4392.5 t of particulate matter (PM), 26.0 t of Pb, 25.8 t of Cr, 15.5 g of Hg, 5.0 t of Cd, 3.4 t of Ni, 273.2 kg of As, and 73.2 g-TEQ of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) were emitted by MSWI in mainland China. The biggest HI and RR at county-level were 2.75E-3 (<1) and 9.11E-7 (<1E-6), and the relatively high-risk regions mainly concentrated in the eastern coastal areas (Shanghai, Jiangsu), and southwestern inland (Sichuan, Chongqing). Besides, the greatest contributor to HI and RR were Pb and PCDD/Fs separately. The identified relatively high-risk areas and pollutants above need to be set as the priority control areas or pollutants in the risk management. Certainly, more field tests are suggested to be conducted in these places to provide more exact information.