Rapid Increase in Cement-Related Mercury Emissions and Deposition in China during 2005-2015

The cement industry has become the largest mercury (Hg) emission source in China. Better understanding Hg emission and deposition characteristics and drivers of Hg emission changes can increase the awareness of related risks and support effective policy making. The results show that due to the substantial increase in the use of new suspension preheater and precalciner (NSP) technology in China, an approximate two-fold increase from 80.0 to 144.0 Mg year-1 was observed for the cement-related Hg emissions during 2005-2015, which has resulted in a considerable increase in atmospheric deposition over terrestrial China from 37.9 to 75.9 Mg year-1. Compared to the great majority of emission sectors, the same increase in Hg emissions from cement production can cause more deposition due to the large share of highly water-soluble divalent Hg in the sector. Each 1% increase in the share of divalent Hg can result in an increase of 0.37 Mg year-1 in deposition over terrestrial China. Technical improvement and diversification of cement products are two major driving forces offsetting the economy-induced growth in cement-related Hg emissions during 2005-2015. Measures aimed at reducing the Hg emission intensity against the further increase in the use of NSP technology and avoiding overcapacity against the stimulation of real estate and increasing cement demands are urgently needed for the cement industry in China.