The endocrine disruptive effects of mercury

Mercury, identified thousands of years ago is one of the oldest toxicants known. The endocrine disruptive effects of mercury have recently become one of the major public concerns. In this report, the adverse effects of mercury on the hypothalamus, pituitary, thyroid, adrenal gland, and gonads (testis and ovary) in laboratory animals as well as in humans are reviewed. The effects of both environmental and occupational exposures to organic, inorganic, or metallic mercury are explained. There is sufficient evidence from animal studies supporting the disruptive effects of mercurials on the functions of the thyroid, adrenal, ovary, and testis, although several factors make it difficult to extrapolate the animal data to the human situation. However, the human studies performed so far, which focused mainly on serum hormone levels, failed to provide any conclusive data to confirm the findings from the animal studies. Therefore, further well-designed epidemiological studies are urgently needed. The possible mechanisms of the toxic effects are also discussed. The broad enzyme inhibition and the influence on the combining of hormones by their receptors, which seem due to its avid binding to sulphydryl, may account for the primary mechanism. The interference with intracellular calcium metabolism, and peroxidation may also be involved.