An inventory of mercury emissions from anthropogenic activities in China is compiled for the year 1999 from official statistical data. We estimate that China's emissions were 536 (7236) t of total mercury. This value includes open biomass burning, but does not include natural sources or re-emission of previously deposited mercury. Approximately 45% of the Hg comes from non-ferrous metals smelting, 38% from coal combustion, and 17% from miscellaneous activities, of which battery and fluorescent lamp production and cement production are the largest. Emissions are heaviest in Liaoning and Guangdong Provinces, where extensive smelting occurs, and in Guizhou Province, where there is much small-scale combustion of high-Hg coal without emission control devices. Emissions are gridded at 30 Â 30 min spatial resolution. We estimate that 56% of the Hg in China is released as Hg 0 , 32% as Hg 2+ , and 12% as Hg p. Particulate mercury emissions are high in China due to heavy burning of coal in residential and small industrial settings without PM controls. Emissions of Hg 2+ from coal-fired power plants are high due to the absence of flue-gas desulfurization units, which tend to dissolve the soluble divalent mercury. Metals smelting operations favor the production of elemental mercury. Much of the Hg is released from small-scale activities in rather remote areas, and therefore the activity levels are quite uncertain. Also, emissions test data for Chinese sources are lacking, causing uncertainties in Hg emission factors and removal efficiencies. Overall, we calculate an uncertainty level of 744% (95% confidence interval) in the estimate of total emissions. We recommend field testing of coal combustors and smelters in China to improve the accuracy of these estimates.

We have developed multiple-year inventories of anthropogenic mercury emissions in China for 1995 through 2003. We estimate that total Hg emissions from all anthropogenic sources increased at an average annual rate of 2.9% during the period 1995-2003, reaching 696 (+/- 307) t in 2003, with a speciation split of 395 t of Hg0, 230 t of Hg2+, and 70 t of Hg(p). Nonferrous metals smelting and coal combustion continue to be the two leading mercury sources in China, as nonferrous metals production and coal consumption keep increasing. Nonferrous metals smelting and coal combustion together contributed approximately 80% of total Hg emissions during the past decade. Hg emissions from coal combustion increased from 202 t in 1995 to 257 t in 2003 at an average annual rate of 3.0%. Among all of the coal consumption sectors, the power sector is the leading one in Hg emissions growth, up by 5.9% annually. Hg emissions from nonferrous metals smelting increased from 230 t in 1995 to 321 t in 2003 at an average annual rate of 4.2%. Although Hg emissions related to gold smelting decreased since 1996, other nonferrous metals such as zinc, lead, and copper contributed significant Hg growth at annual rates of 8.5%, 13.0%, and 6.9%, respectively. At provincial level, the trends of Hg emissions show significant variation. The uncertainty level decreased from +/- 78% (95% confidence interval) in the estimate of total emissions in 1995, to +/- 44% in 2003. This is primarily attributed to the decreased emissions from those Hg sources with the largest uncertainty in both activity levels and emission factors, such as artisanal gold smelting, mercury mining, and battery/fluorescent lamp production.