Chromium [Cr, 24]

Chromium (Cr), a metal of the group 6 in the periodic table of elements, has strong lithophillic tendencies. Chromium is mined mainly as chromite ore, which is converted into ferrochromium, broadly used in metallurgical industries, and most of that is consumed to make stainless and heat-resisting steel. Cr contents of surface soils have increased due to pollution from various sources, of which the main are chromite-ore processing residue, municipal, and tannery and leather-manufacturing wastes. Mean Cr contents of two moss species from mountains in Poland are a little bit lower than in the same moss species from Alaska. Humans can be exposed to Cr by breathing air, drinking water, eating food Cr, or through skin contact with Cr compounds. The most common health problem in workers exposed to Cr involves the respiratory tract. Chromium is a component of enzymes that controls glucose metabolism and synthesis of fatty acids and cholesterol.