Global mercury emissions to the atmosphere from anthropogenic and natural sources

This chapter provides an up-to-date overview of global mercury emissions from natural and anthropogenic sources at country and regional/continental scale. The information reported in Chapters 2-8 is the basis of the assessment reported in this chapter, however, emissions data related to sources and regions not reported in chapters 2-8 have been derived, at the extent possible, from the most recent peer-reviewed literature and from official technical reports. Natural sources, which include the contribution from oceans and other surface waters, rocks, top soils and vegetation, volcanoes and other geothermal activities and biomass burning are estimated to release annually about 5207 Mg of mercury, part of which represent previously deposited anthropogenic and natural mercury from the atmosphere to ecosystem-receptors due to historic releases and part is a new contribution from natural reservoirs. Current anthropogenic sources, which include a large number of industrial point sources are estimated to release about 2536 Mg of mercury on annual basis, the major contribution is from fossil fuels fired power plants (1422 Mg y-1), artisanal small scale gold mining (400 Mg y-1), waste disposal (166 Mg y-1), non-ferrous metals manufacturing (156 Mg y-1) and cement production (140 Mg y-1). Our current estimate of global emissions suggest that summing up the contribution from natural and anthropogenic sources nearly 7743 Mg of mercury is released annually to the global atmosphere. The evaluation of global emissions presented in this report differs from previous published assessments because in the past, emissions from several sources, i.e., forest fires and cold-bed fires have not been accounted for and also because of improved knowledge of some anthropogenic and natural sources (i.e., emissions from oceans, vegetation) as suggested form most up-to-date literature.