Global mercury pollution and its expected decrease after a mercury trade ban

The high toxicity of methyl mercury (MeHg) is well known, as is the existence of transformations between metallic Hg and MeHg. As a consequence the industrialised countries have adopted Hg-free products and processes, because a continued use of Hg would result in diffuse emissions even if used Hg is recycled. However, Western Europe exports about 100 tons of Hg to Brazil each year, where it is emitted over the Amazon. The export from Europe began during the 1980s, when a gold mining boom spread like wildfire in the Amazon. Mercury agglutinates gold grains by forming an amalgam. Later on the gold is purified from the Hg by heating. The Hg evaporates into the air and is subsequently deposited onto land and in surface waters. Another important Hg polluter is China, which has increased its burning of coal without appropriate smoke cleaning devices and is also importing considerable amounts of Hg for industrial use and for use in gold mining. Regional Hg emissions contribute to global Hg pollution due to the mobility of Hg. A ban on the Hg trade in Europe and North America would significantly diminish global Hg pollution. A ban would also result in the closing of the state-owned Hg mine (MAYASA) in Almaden, Spain, the world's most important anthropogenic Hg source.