The Minnesota Department of Health has set new guidance for manganese in drinking water for formula-fed infants.
Manganese is a naturally-occurring element that we need in our diets. But infants don't need much, and most infant formula contains enough for them. If there's excess manganese in the drinking water used to mix the formula, they may get too much and develop learning and behavior problems.
Health Department toxicologist Kate Sande said this mostly happens to people with private wells.
"What we recommend in those cases is that they give us a call, so if they're aware they have manganese in their water we can give advice on how to reduce their exposures," Sande said.
Sande said some filters will reduce manganese.
The guidance is 100-parts-per-billion for infants, and 300-parts-per-billion for children and adults.
"They're protective during pregnancy, but we do need to get the message out that if they have a newborn baby, they may need to take additional action if that baby is going to be fed formula mixed with the water," Sande said.
Manganese can leach from landfills and mine waste dumps.