Northfield residents are advised to filter manganese from the water infants drink.
The recommendation, announced Thursday in a press release, pertains to children one years old or younger. MDH has set new guidance levels for manganese in drinking water for that age range. For infants who drink tap water or formula made from tap water, the level is considered 100 micrograms per liter or less.
“For infants who never drink tap water or formula made from tap water and everyone in your household over 1 year old, the level is 300 micrograms per liter or less,” the city stated in a press release.
In the release, the city said homeowners can remove manganese by carbon filter, a distillation system or distilled water, through a water filtration system, by a reverse osmosis water system or water softener.
MDH Community Water Supply Unit Communications Planner Anna Arkin said although no specific health impacts have been shown to come from elevated levels of manganese, the substance has been associated with learning and behavior problems after elevated infant exposure. Children and adults with elevated levels of manganese are thought to be at higher risk of memory, attention and motor skill issues.
The city of Northfield, in conjunction with the Minnesota Department of Health, took water samples June 20 as part of routine drinking water testing. Results are expected within the next two to three months.
The release states the city expects manganese results to be slightly over 100 micrograms per liter based on samples taken in 2012.
Per the U.S. Environmental Protection Agency, public water systems are not required to treat for manganese within drinking water. The substance, considered an essential nutrient in proper amounts, is considered naturally occurring in drinking water and can be found in rocks and soil.
MDH derives health-based guidelines based on toxicology studies, often on lab animals. The department evaluates correlated studies for humans.