Mercury emission inventory and its spatial characteristics in the Pearl River Delta region, China

A 3 km × 3 km gridded mercury emission inventory in the Pearl River Delta (PRD) region for 2008 was compiled from the best available emission factors and official statistical data. The inventory presented a comprehensive estimation of anthropogenic mercury sources and roughly estimated the emissions from natural sources. The total mercury emissions in the PRD region for the year of 2008 are estimated to be 17,244 kg, of which 85% released as Hg(0), 11% as Hg(2+), and 4% as Hg(P). Anthropogenic activities are dominant sources, accounting for 91% of the total emissions, while natural sources constitute the remaining emissions. Ranking by cities, Foshan produces the largest mercury emissions, followed by Dongguan, Guangzhou and Jiangmen. Coal combustion, municipal solid waste (MSW) incineration, fluorescent lamp and battery production are dominant contributors, responsible for 28%, 21%, 19% and 16% of the anthropogenic emissions, respectively. The high contribution of MSW incineration results from the rapid growth of MSW incineration in this region, reflecting a new trend of mercury emissions in China, especially in the fast developing regions. This implies the urgent need for further investigation of mercury emissions and the importance of controlling mercury emissions from MSW incineration.