Manganese

Manganese is a silvery-gray metal that that resembles iron. It is the 12th most abundant element in the earth's crust. In nature, manganese is always found in combination with another metal, most often with iron. It is a hard, brittle metal that oxidizes easily. Because of it similarities with iron, manganese is useful in the production of alloys, particularly stainless steel. Manganese can also be found in alkaline batteries. It has been used as an antiknock additive to gasoline and as a pigment for ceramics and glass. It is now used in the U.S. as part of the alloy for gold dollar coins.

For the general population, exposure to manganese occurs mainly by ingestion of food. Nuts and grains are naturally rich in manganese. Other dietary sources may include tea, beans, and leafy green vegetables. Infant formulas based on soy may contain 10-50 times higher concentrations of manganese than breast milk contains.

Manganese in drinking water or air has been shown in some circumstances to result in significant exposures. Occupational exposures most likely occur by inhaling manganese vapors in the workplace.

Common exposure thresholds

The U.S. Environmental Protection Agency has not developed a primary standard for manganese in drinking water. The secondary maximum contamination level (MCL) is 0.05 milligrams per liter (mg/L). Secondary drinking water standards are non-mandatory water quality standards for aesthetic (taste, color, smell) and technical concerns.

Adult urine typically has less than 10 micrograms of manganese per liter of urine (10 μg/L).

The 4CSBC uses the National Health and Nutrition Examination Survey (NHANES) 95th percentile level as a screening threshold. Only five percent of the NHANES participants (representing the American population) have levels that exceed the 95th percentile level. Everyone else is below that level. Thus, that level is considered elevated. It may or may not be harmful. The 95th percentile screening threshold for manganese is 0.4 μg/L

Health concerns

Manganese is an essential nutrient. It is important for a number of metabolic and antioxidant pathways in our bodies. Too much manganese, however, can cause neurological problems. Most adults are able to maintain the right levels of manganese. Iron deficiency may cause an increase in manganese absorption and retention. Women tend to have higher levels of manganese in their bodies than men.

Adverse Health Effects:

Sources of additional information

Agency for Toxic Substances and Disease Registry (ATSDR)

Centers for Disease Control and Prevention (CDC)

U.S. Environmental Protection Agency (EPA)

Papers

Last Update: May 5, 2016