Global Mercury Assessment 
shows that humans and wildlife are at risk

The Global Mercury Assessment finds that environmental mercury levels have increased considerably since the on-set of the industrial age. Mercury is now present in various media and food (especially fish) all over the globe at levels that adversely affect humans and wildlife. Widespread exposures are occurring due to human-generated sources. Even regions with no significant mercury releases, such as the Arctic, are adversely affected due to long-range transport of mercury
Mercury is highly toxic, especially to the developing nervous system. Some populations are especially susceptible, most notably the fetus and young children. Yet mercury continues to be used in many products and processes all over the world, including in small-scale gold mining; manometers and thermometers; electrical switches; fluorescent lamps; dental amalgams, and some pharmaceuticals. The most significant mercury releases to the environment are emissions to air, but mercury is also released from sources directly to water and land. Important emissions sources include: coal-fired power generation, waste incineration, cement, steel and chloralkali production, 

         A coal-fired powerplant/FreeFoto.com

mining, cremation and landfills. 

Gold panning in Lao PDR/UNIDO

Once released, mercury persists in the environment where it circulates between air, water, soils and biota in various forms. Once deposited, the form can change (by microbes) to methylmercury, a particularly hazardous form that concentrates up food chains, especially the aquatic food chain. Most people are primarily exposed to methylmercury through the diet (especially fish) and to elemental mercury due to dental amalgams and occupations (such as small-scale gold mining). Other sources of exposure include skin-lightening creams, mercury used for ritualistic purposes and in traditional medicines and mercury spills in the home.
Fish are a valuable, nutritious component of the human diet. Mercury is a major threat to this important food supply. Elevated mercury levels have been measured in numerous fish species throughout the world, with the highest levels found in large predatory fish. Humans who consume significant amounts of contaminated fish are at risk. Also, wildlife that rely on fish as a large part of their diet, such as otters, eagles, seals and some whales, often have considerably elevated mercury levels.

Many nations have implemented actions to limit mercury uses, releases and exposures. However, further actions are needed to protect humans and wildlife from mercury pollution.

FAO/Danilo Cedrone