Two-pathway perspective for heavy metal emission mitigation: A case study of Guangdong Province, China

Heavy metal emissions have attracted much worldwide attention for its recalcitrance and persistence. In this study, a two-pathway environmental simulation model is developed to uncover heavy metal emissions as induced by intra-provincial production and extra-provincial investments, filling the gap of mitigating heavy metal emissions from separate pathway. This developed model is applied to Guangdong Province, China targeting on the mitigation of Hg, As, Cd, Cr, and Pb emissions. Additionally, emission reduction simulations are implemented on the basis of key sector identification. The effects of intra-provincial production reduction are more notable than those of extra-provincial investment reduction. In addition, mitigation of Hg and As emissions can be achieved through the reduction in both intra-provincial production and extra-provincial investment. In the contrast, it is not expected that the reduction of extra-provincial investment be duo to the emission mitigation of Cd, Cr and Pb. Moreover, an examination of five optimized scenarios reveals that the most remarkable emission mitigation pathway is the reduction of intra- and extra-provincial activities. This study is an indispensable reference for multi-pathway emission mitigation for heavy metals.