Manganese exposure occurs when a person comes in contact with high levels of the metallic element manganese. This can happen through the intake of food and water with abnormally high manganese levels or by inhaling airborne manganese.
Manganese is an essential mineral found in some rocks, soil, and foods. Although manganese is an important part in a person's everyday diet, exposure to too much manganese can pose a serious health threat.
Manganese is a metallic element. When comparing tonnage, manganese is the fourth most used metal in the world, behind iron, aluminum, and copper. Manganese plays an important role in the production of steel and in everyday health. It is an essential mineral, meaning manganese must be part of a person's everyday diet for optimal health and body function.
Manganese can be found naturally in many foods, such as nuts, legumes, seeds, whole grains, leafy green vegetables, and tea. People who do not get enough manganese from their everyday diet may take manganese supplements. Manganese is also found in low levels in soil and in ground and drinking water. Health organizations agree that the upper limit for daily manganese intake is 11 mg. Consuming more manganese than this daily can be very harmful to one's health.
Manganese is also found in some rocks and plays a vital role in the production of steel. It gives steel the ability to be harder, stiffer, and stronger. People with occupations that involve working with steel have a higher risk of being exposed to unsafe levels of manganese. Manganese particles enter the air when welding or steel production takes place. These particles can then be breathed in by workers. Manganese exposure is an important workplace safety issue and has been the subject of many lawsuits.
There are three ways people are exposed to manganese. The first, and most common way, is through eating foods that contain manganese or by taking manganese-containing supplements. Drinking, swimming, or bathing in water containing manganese is the second way people are exposed to the mineral. Finally, people who work in factories that make steel or in occupations such as welding may be exposed to high levels of airborne manganese.
The most common problem experienced by people who are exposed to high levels of manganese involves the nervous system. These people may show signs of behavioral changes, become slow and clumsy, and have trouble with movements. Symptoms of manganese exposure often are compared to the symptoms of Parkinson's disease, with noticeable tremors and other neurological symptoms. People exposed to lower, yet still unsafe, levels of manganese may show signs of slow movement, such as in the hands. Some studies have shown that manganese workers have fertility problems or a higher rate of low birth weight babies and greater likelihood of offspring with birth defects.
Children exposed to unsafe levels of manganese have shown abnormal brain development. This includes behavioral changes and difficulty learning and remembering. A 2010 study done in Canada found that children who were exposed to higher levels manganese at home through tap water averaged six points lower on IQ tests than children who had little or no manganese in their tap water. This was true even when all water in the study met Canada's guidelines for safe manganese concentrations.
Testing for manganese exposure can be done through blood, urine, hair, or fecal exams. While low levels of manganese are always found within the body, these tests can allow physicians to see if a person has abnormal amounts of manganese in their system. Past exposures to manganese are hard to measure because in a healthy person, manganese is removed from the body within a few days. People who have been exposed to higher concentrations of manganese over a longer period will need medical treatment.
Chelation therapy, a treatment used for many types of heavy metal poisonings, may be used. The drug edetate calcium disodium is intravenously administered and travels through the blood stream gathering the manganese. This manganese will later be removed from the body through the urine. The entire process takes around 48 hours to complete and can only be performed by a professional who has been trained in chelation therapy. The use of chelation therapy has had very good results, but it may not be completely successful in the treatment of people who have had ongoing exposure to unsafe levels of manganese. By the time symptoms appear, it is often too late to just remove manganese from the body as treatment. As of 2012, there were no approved cures for the neurological and Parkinson's-like symptoms that go along with chronic manganese poisoning. Instead, focus is geared toward managing symptoms and slowing the progression of the disease.
Chelation therapy generally is very successful in the treatment of patients who have acute or short-term manganese exposure. People who have had chronic manganese exposure and have developed symptoms of severe neurological damage are unlikely to be cured using chelation therapy. Focus is on managing symptoms and the progression of the disease. Even with treatment, the symptoms of manganese poisoning are often irreversible.
The best prevention against manganese exposure is through eating a healthy and well-balanced diet. By drinking, bathing, and swimming in water that meets health standards and not taking an unnecessary amount of manganese supplements, the average person should not be at risk for manganese exposure. People with liver disease should speak to their physician about the amount of manganese in their diet.
People whose occupation puts them at risk for being exposed to high levels of manganese should take precautions at their workplace. This includes removing work clothes that may be covered in manganese dust before returning home, wearing an appropriate mask at work to limit the amount of manganese breathed in, and doing work such as welding in well-ventilated areas. The United States Food and Drug Administration has set limits on the amount of manganese allowed in bottled water (0.05 mg/L) and the Occupational Health and Safety Administration has established a limit for manganese concentration in workplace air (5 mg/m3). These limits have been establish to protect workers and everyday citizens from manganese exposure.
Menezes-Filho, Jose, et al. “Elevated Manganese and Cognitive Performance in School-Aged Children and Their Mothers.” Environmental Research. (2011) 111(1): 156–163. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3026060 (accessed October 15, 2012).
Agency for Toxic Substances and Disease Registry. “Manganese.” http://www.atsdr.cdc.gov/tfacts151.pdf (accessed October 15, 2012).
Agency for Toxic Substances and Disease Registry. “Public Health Statement.” http://www.atsdr.cdc.gov/toxprofiles/tp151-c1.pdf (accessed October 15, 2012).
U.S. EPA and Toxicity and Exposure Assessment for Children's Health. “Mangansese TEACH Chemical Summary.” http://www.epa.gov/teach/chem_summ/manganese_summary.pdf (accessed October 15, 2012).
Agency for Toxic Substances and Disease Registry, 4770 Buford Hwy, NE, Atlanta, GA, 30341, (800) 232-4636; TTY: (888) 232-6348, firstname.lastname@example.org, http://www.atsdr.cdc.gov/ .
International Manganese Institute, 17 rue Duphot, Paris, France, +33(0) 145 63 06 34, Fax: +33 (0) 1 42 89 42 92, http://www.manganese.org .
United States Environmental Protection Agency (EPA), Ariel Rios Building, 1200 Pennsylvania Avenue, N.W., Washington, DC, 20460, (202) 272-0167; TTY (202) 272-0165, http://www.epa.gov .
Tish Davidson, AM