Quantitative assessment of atmospheric emissions of toxic heavy metals from anthropogenic sources in China: historical trend, spatial distribution, uncertainties, and control policies

摘要

Anthropogenic atmospheric emissions of typical toxic heavymetals have caused worldwide concern due to their adverse effects onhuman health and the ecosystem. By determining the best availablerepresentation of time-varying emission factors with S-shape curves, weestablish the multiyear comprehensive atmospheric emission inventories of 12typical toxic heavy metals (Hg, As, Se, Pb, Cd, Cr, Ni, Sb, Mn, Co, Cu, andZn) from primary anthropogenic activities in China for the period of1949–2012 for the first time. Further, we allocate the annual emissions ofthese heavy metals in 2010 at a high spatial resolution of 0.5° × 0.5° grid with ArcGIS methodology and surrogateindexes, such as regional population and gross domestic product (GDP). Ourresults show that the historical emissions of Hg, As, Se, Cd, Cr, Ni, Sb,Mn, Co, Cu, and Zn, during the period of 1949–2012, increased byabout 22–128 times at an annual average growth rate of 5.1–8.0 %,reaching about 526.9–22 319.6 t in 2012. Nonferrous metal smelting, coalcombustion of industrial boilers, brake and tyre wear, and ferrous metalsmelting represent the dominant sources of heavy metal emissions. In terms of spatial variation, themajority of emissions are concentrated in relatively developed regions,especially for the northern, eastern, and southern coastal regions. Inaddition, because of the flourishing nonferrous metal smelting industry,several southwestern and central-southern provinces play a prominent role insome specific toxic heavy metals emissions, like Hg in Guizhou and As inYunnan. Finally, integrated countermeasures are proposed to minimize thefinal toxic heavy metals discharge on account of the current and futuredemand of energy-saving and pollution reduction in China.