ABSTRACT
Molybdenum is an essential trace element that is ubiquitous in the environment and vital in plant and animal biochemistry. In human nutrition Mo is assimilated primarily from vegetables. It is closely associated with copper and iron metabolism and enzymatic redox processes involving an equilibrium between the Mo6, Mo5, and Mo4 forms, e.g., in the oxidation of aldehydes, sulfites and nitrates, and of molecular nitrogen (1). In plants, the so-called MoFe protein, a component of nitrogenase, is essential for nitrogen fixation (2). Toxic levels of molybdenum are rarely attained, as the metal is rapidly eliminated renally from mammalian organisms. In humans, gout, characterized by high levels of uric acid excretion, is more prevalent in regions with high Mo concentrations in agricultural soil and plants (3). High levels of exposure to Mo as the mineral dust occur in the foundry industry and in molybdenum ore mining.
