Molybdenum [Mo, 42]

Molybdenum, a metal of the group 6 in the periodic table of elements, occurs in the Earth’s crust at the mean content of 1.5 mg/kg, within the range of 1–2 mg/kg. Molybdenum in seawater is relatively unreactive; in oxygenated conditions its concentration is rather stable, whereas in anoxic water, it readily precipitates in bottom sediments. Molybdenum is moderately mobile in plants, and there is an assumption that molybdenum-sulfur amino acid complexes are involved in this process. Molybdenum concentrations in plants closely reflect its mobile pool in soils, as it is readily taken up by plants, when present in soluble species. Vegetables grown in Molybdenum-polluted soils, near a Molybdenum-processing plant, accumulated this element from 124 to 1061 mg/kg in lettuce and cabbage, respectively. Increased exposure at the work place, or through drinking water, is balanced by increased urinary excretion. Raised blood levels are seen in uremia, rheumatic disorders, and cardiovascular disease.