Heavy metal Manganese (Mn)

Manganese is an essential micro-nutrient for plants and animals. Its deficiency in humans may cause diabetes, nervous instability, convulsions, disorders of cartilaginous, growth in infants and children, and rheumatoid arthritis exposure to layer than trace concentration of Manganese can be toxic.

The metal is a respiratory irritant and systematic poison when inhaled mainly as oxides in excessive amounts. The major source of manganese pollution is the processing of iron ores, in which manganese is present in significant concentrations.

Industrial toxicity through inhalation of manganese particulates is of two types.

a) The first is due to acute short term exposure and is known as manganese pneumonity persons working in plants with high concentrations of manganese dust an incidence of respiratory diseases 30 times greater than normal. Pathological changes include epithelialneerosin followed by mono nuclear proliferation.

b) The second and more serious disease is caused by chronic inhalation of MnO2, generally over a period of more than 2 years it involves the central nervous system chronic manganese poisoning known as manganism leads to psychiatric disorders characterized by irritability difficulty in walking, speech disturbances, and compulsive behavior that may include running, fighting and singing. If the condition persists a mask like face, retropulsion or propulsion and a Parkinson like syndrome develops. In addition to the injuries to central nervous system, liver cirrhosis has been observed frequently, victims of chronic manganese poisoning recovers slowly, even when exposure is removed.