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

TLDR

Anthropogenic atmospheric emissions of toxic heavy metals have raised global concerns due to their harmful effects on human health and ecosystems. The study aims to develop the first multiyear atmospheric emission inventories for 12 toxic heavy metals in China (1949–2012) by fitting S‑shaped time‑varying emission factors and to propose integrated countermeasures. Emission factors were modeled with S‑shaped curves, inventories compiled for 12 metals, and 2010 annual emissions were spatially allocated to 0.5° × 0.5° grids using ArcGIS and surrogate indicators such as population and GDP. Historical emissions increased 22–128× (annual growth 5.1–8.0 %) reaching 526.9–22 319.6 t in 2012, with nonferrous smelting, coal combustion, brake/tyre wear, and ferrous smelting as dominant sources, and emissions concentrated in developed coastal regions and specific provinces like Guizhou for Hg and Yunnan for As. Abstract.

Abstract

Abstract. Anthropogenic atmospheric emissions of typical toxic heavy metals have caused worldwide concern due to their adverse effects on human health and the ecosystem. By determining the best available representation of time-varying emission factors with S-shape curves, we establish the multiyear comprehensive atmospheric emission inventories of 12 typical toxic heavy metals (Hg, As, Se, Pb, Cd, Cr, Ni, Sb, Mn, Co, Cu, and Zn) from primary anthropogenic activities in China for the period of 1949–2012 for the first time. Further, we allocate the annual emissions of these heavy metals in 2010 at a high spatial resolution of 0.5° × 0.5° grid with ArcGIS methodology and surrogate indexes, such as regional population and gross domestic product (GDP). Our results 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 by about 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, coal combustion of industrial boilers, brake and tyre wear, and ferrous metal smelting represent the dominant sources of heavy metal emissions. In terms of spatial variation, the majority of emissions are concentrated in relatively developed regions, especially for the northern, eastern, and southern coastal regions. In addition, because of the flourishing nonferrous metal smelting industry, several southwestern and central-southern provinces play a prominent role in some specific toxic heavy metals emissions, like Hg in Guizhou and As in Yunnan. Finally, integrated countermeasures are proposed to minimize the final toxic heavy metals discharge on account of the current and future demand of energy-saving and pollution reduction in China.