Sources And Fluxes Of Harmful Metals

Metals are important chemicals occurring in various ecosystems. Some of them are toxic, some are toxic when appearing in excess and some are essential for the environment and human health. They are ubiquitous constituents of various natural materials in the lithosphere, the hydrosphere and the biosphere.High-temperature processes in the primary non-ferrous metal industries are the major source of atmospheric arsenic (As), cadmium (Cd), copper (Cu), indium (In), antimony (Sb), and zinc (Zn), and an important source of lead (Pb) and selenium (Se). Combustion of coal in electric power plants and industrial, commercial, and residential burners is the major source of anthropogenic mercury (Hg), molybdenum (Mo), and selenium and a signifi cant source of arsenic, chromium (Cr), manganese (Mn), antimony, and thallium (Tl). Combustion of oil for the same purpose is the most important source of vanadium (V) and nickel (Ni). Combustion of leaded gasoline is estimated to be the major source of lead. Atmospheric chromium and manganese derive primarily from the iron and steel industry. The largest discharges of these metals are estimated for soils followed by discharges to water.The degree of human alteration of metals biogeochemical cycles caused by their anthropogenic emissions affects human health impacts of these chemicals. The information on alteration degree on global and regional scale is discussed.Emissions of metals from various anthropogenic sources can be reduced using technological (e.g. Best Available Technology (BAT) solutions) and non-technological measures (e.g. Best Environment Practice (BEP) option). Various emission reduction measures are presented.