• cadmium
  • One of the toxic heavy metal which has caused deaths and permanent illnesses in a series of major pollution incidents around the world. Cadmium has no useful biological purpose. However, it has wide industrial applications. It has been used for decades in metal plating to prevent corrosion, in rechargeable batteries and as a pigment in certain plastics and paints. Special care is taken in the industrial smelting of ores and subsequent handling of cadmium, because occupational exposure is known to have caused heart, chest and kidney disorders. Environmental health problems have come from exposure to various sources of pollution.
Abstract from DBPedia
    Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Like zinc, it demonstrates oxidation state +2 in most of its compounds, and like mercury, it has a lower melting point than the transition metals in groups 3 through 11. Cadmium and its congeners in group 12 are often not considered transition metals, in that they do not have partly filled d or f electron shells in the elemental or common oxidation states. The average concentration of cadmium in Earth's crust is between 0.1 and 0.5 parts per million (ppm). It was discovered in 1817 simultaneously by Stromeyer and Hermann, both in Germany, as an impurity in zinc carbonate. Cadmium occurs as a minor component in most zinc ores and is a byproduct of zinc production. Cadmium was used for a long time as a corrosion-resistant plating on steel, and cadmium compounds are used as red, orange and yellow pigments, to color glass, and to stabilize plastic. Cadmium use is generally decreasing because it is toxic (it is specifically listed in the European Restriction of Hazardous Substances Directive) and nickel-cadmium batteries have been replaced with nickel-metal hydride and lithium-ion batteries. One of its few new uses is in cadmium telluride solar panels. Although cadmium has no known biological function in higher organisms, a cadmium-dependent carbonic anhydrase has been found in marine diatoms.

    カドミウム(英: cadmium [ˈkædmiəm])は、原子番号48の金属元素で、元素記号は Cd である。亜鉛族元素の1つであり、化学的挙動は亜鉛と似ており、常に亜鉛鉱にカドミウムも含まれているため、亜鉛精錬の際に回収されている。 有害物質として知られる。人体にとって有害であり、体内に吸収されると腎臓に機能障害を引き起こすなどするため、取り扱い、及び、鉱山などからの排水の管理には注意を要する。日本ではカドミウムによる環境汚染により、富山県の神通川流域で発生したイタイイタイ病が問題となった。また、カドミウムとその化合物は、WHOの下部機関IARCよりヒトに対して発癌性を有する (Group1) と勧告されている。 ホタテガイの中腸腺(ウロ)には、カドミウムが蓄積する事が知られている。