Manganese in Drinking Water Manganese is a common element found in minerals, rocks, and soil. It is also a normal part of a healthydiet, but can be harmful if consumed in excess. Manganese is found naturally in groundwater, but levels can be increased by underground pollution sources. Manganese may become noticeable in water at levels greater than 50 micrograms per liter of water (µg/L). At this level, the water will have a brown color and leave black deposits on bathroom fixtures. The US Environmental Protection Agency has recently set a drinking water health advisory for manganese of 300 µg/L. If you have manganese in your drinking water, this fact sheet can help you understand the health risks and evaluate your need for a water treatment system.
How do I know if I have manganese in my water?
Manganese may be in your water if it has a rust color, causes staining of faucets, sinks, or laundry, and has an off-taste or odor. If this is the case, you should have your water tested for manganese by a state-certified water testing laboratory. You can find a certified laboratory by searching the telephone directory under “Laboratories- Testing” or by searching the lab lists on the Department of Natural Resources website: http://dnr.wi.gov/org/es/science/lc/LABS/Lablists.htm .To help you understand the results, you can contact your local health department (http://dhfs.wisconsin.gov/localhealth) or call the Department of Health and Family Services (DHFS) in your state.
What is the normal amount of manganese in well water?
Manganese levels in well water vary throughout New England. However, some wells have levels that are above the health advisory of 300 µg/L. If your water has an off taste, color, or odor, and causes staining in sinks or on laundry, you should have your water tested.
How much manganese is too much?
Manganese levels below 300 µg/L are generally not a health concern. As previously mentioned, infants should not drink water that is above the health advisory level of 300 µg/L Also, people who drink more than 8 cups of water a day and have a liver disease should also avoid drinking water that is above the health advisory level. If your water tests higher than the health advisory level, find a different source of safe water to drink.
What health effects can manganese cause?
Many years of exposure to high levels of manganese can cause harm to the nervous system. A disorder similar to Parkinson’s disease can result. This type of effect is most likely to occur in the elderly. The federal health advisory for manganese is intended to protect against this effect.
Is manganese of concern for infants and young children?
Yes, especially for bottle-fed infants. Certain baby formulas contain manganese as a nutrient, and if prepared with water that also contains manganese, the infant may get a higher dose than the rest of the family. In addition, young children appear to absorb more but excrete less manganese than older age groups. This adds up to agreater potential for exposure in the very young. Some studies suggest that early childhood and prenatal
exposures to manganese can have effects on learning and behavior. Thus, it is very important to know what the manganese levels in drinking water are when using it to make baby formula.
How else can I be exposed to manganese?
Manganese is found in small amounts in meat and vegetables. A normal diet provides 2000 to 5000 µg manganese per day. Mineral supplements may contain as much as 5000 µg of manganese. As a comparison, drinking 8 cups of water at 300 µg/L would contribute 600 µg of manganese to one’s diet.
Are there federal standards for manganese in drinking water?
Manganese levels are not regulated in public water supplies. However, the US Environmental Protection Agency has established an aesthetic water quality standard of 50 µg/L. Manganese levels below 50 µg/L should prevent the staining of bathroom fixtures and laundry. This standard is lower than the health advisory and will protect public health.
How can I decrease my family's exposure to manganese?
Manganese levels lower than 300 µg/L can affect the color and taste of the water. You should treat your water or buy bottled water if the manganese level is greater than 300 µg/L. Many times people choose to treat their water if the level is above 50 µg/L. Manganese treatment devices must be installed by a licensed plumber. If the system was sold to you for manganese removal and was not approved for that purpose, you may be eligible for a refund.
Does Manganese Inhaled from the Shower Represent a Public Health Threat?
WINSTON-SALEM, N.C. – A new analysis based on animal studies suggests that showering in manganese-contaminated water for a decade or more could have permanent effects on the nervous system. The damage may occur even at levels of manganese considered safe by the Environmental Protection Agency, according to researchers from Wake Forest University School of Medicine.
“If our results are confirmed, they could have profound implications for the nation and the world,” said John Spangler, M.D., an associate professor of family medicine. “Nearly 9 million people in the United States are exposed to manganese levels that our study shows may cause toxic effects.”
The study is the first to show the potential for permanent brain damage from breathing vaporized manganese during a shower. It was conducted by reviewing the medical literature and calculating, based on animal studies, the amount of manganese people would absorb by showering 10 minutes a day.
Because manganese is monitored in public water supplies, high levels of this naturally occurring metal are especially found in wells and private water supplies.
Spangler and Robert Elsner, Ph.D., published their findings in the current issue of Medical Hypotheses, a forum for ideas in medicine and related biomedical sciences.
The journal publishes “interesting and important theoretical papers that foster the diversity and debate upon which the scientific process thrives.”
Everyone is exposed to small levels of manganese, which is found in food and many types of rocks and enters the air, soil and water. But, at higher levels, manganese is toxic to the central nervous system and can cause learning and coordination disabilities, behavioral changes and a condition that is similar to Parkinson’s disease.
Children, pregnant women, the elderly, and patients with liver disease are at highest risk from manganese toxicity. Some of these groups have developed manganese poisoning even at fairly low doses in their water supplies, Spangler said.
The Environmental Protection Agency (EPA) has set 0.05 milligrams/liter as the upper limit of manganese advisable in water supplies. The limit, however, is based on odor and taste of the water. The potential risk of manganese accumulating in the brain through showering has not been considered by the EPA in setting this limit. In their analysis, Spangler and Elsner found that concentrations well below 0.05 milligrams might lead to brain injury.
“Inhaling manganese, rather than eating or drinking it, is far more efficient at delivering manganese to the brain,” said Spangler. “The nerve cells involved in smell are a direct pathway for toxins to enter the brain. Once inside these small nerves, manganese can travel throughout the brain.”
Elsner and Spangler extrapolated data from rodents to estimate human exposure to manganese during showering. They found that after 10 years of showering in manganese contaminated water, children would be exposed to doses of manganese three times higher than doses that resulted in manganese deposits in the brains of rats. Adults would be exposed to doses 50 percent higher than the rodents.
The researchers said that while limitations to their calculations do exist, regulatory agencies have not considered this potential pathway when setting drinking water standards.
“Studies should be carried out among populations that have experienced high levels of manganese in their water supplies over long periods of time,” Spangler said. “Regulatory agencies may one day need to rethink existing drinking water standards for manganese.”
The addition of manganese to gasoline as an anti-knock agent may also be a threat, the researchers said.
“The manganese, as it settles from car exhaust onto streets and highways, may enter the water supply, increasing manganese levels in the water we drink and bathe in,” said Spangler.