Global Mercury Emissions to the Atmosphere from Natural and Anthropogenic Sources

Abstract

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, to 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 2917 Mg of mercury on an annual basis, the major contribution is from fossil fuel-fired power plants (1422 Mg yr-1), artisanal small scale gold mining (400 Mg yr-1), waste disposal (187 Mg yr-1), non-ferrous metals manufacturing (310 Mg yr-1) and cement production (236 Mg yr-1). Our current estimate of global emissions suggest that summing up the contribution from natural and anthropogenic sources nearly 8124 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 coal-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 by the most up-to-date literature.