Global mercury emissions and distribution - an Arctic perspective

Abstract

Mercury is a global environmental problem with both natural and anthropogenic sources. It is internationally recognized as a highly toxic and environmentally hazardous substance. The volatility of elemental mercury and of a number of mercury compounds enables that they can be transported over great distances via the atmosphere. In the polar regions, mercury accumulates in the food chain and poses a threat to the ecosystem and the inhabitants of the area. Atmospheric transport from lower latitudes is the primary source of mercury in the polar regions. Approximately 1/3 of this mercury originates from anthropogenic activities, the largest of which are coal burning power plants, small scale gold mining and non-ferrous metal production. This thesis examines the spatial distribution of global mercury emission data using different methods as well the environmental effects of local sources in the Arctic. To allow modelling of atmospheric transport of mercury and of mercury deposition, the emission datasets include, besides total mercury (HgT), three chemical forms of mercury: gaseous elemental mercury (Hg0), divalent mercury (Hg2+) and mercury bound to other particles (HgP). The spatially distributed emission data for the UN Environment Global Mercury Assessment 2018 is available in a 0.25°×0.25° resolution with three height classes (0–50, 50–150 and >150m).The spatially distributed emissions data are available to research groups and individual scientists for modelling mercury transport and deposition on a global and regional scale. The resulting datasets are also of use for effectiveness evaluation of the Minamata Convention on Mercury.