Risks to infants from manganese in drinking water

Consortium funds pilot study to determine neurodevelopment impact

Minnesota groundwater contains some of the highest naturally occurring manganese levels in North America and that metal makes its way into the state’s drinking water. Although an essential trace nutrient, manganese has the potential to produce adverse neurological changes. Emerging evidence from other countries suggests that even low levels of environmental exposure in school-age children may affect their neurodevelopment.

The EPA has determined safe levels of manganese for adults and extrapolated those levels to children ages 3 and up, but no one has determined what manganese does to fetuses and infants and what exposure levels are considered safe. That lack of data concerns the Minnesota Health Department (MDH).

Babies are at particularly high risk for absorbing too much manganese,” says Patricia McGovern, professor of environmental health sciences at the University of Minnesota School of Public Health. “They can’t clear potential toxins from their systems the way adults can and they don’t metabolize things they ingest as efficiently as adults. If they drink dry formula—which is manganese fortified—diluted with tap water containing manganese, they can get inadvertent high doses.”

This year, McGovern, formerly principal investigator for the National Children’s Study Center at the University, and colleague Michael Georgieff, a neonatologist and professor in the Department of Pediatrics and Child Development, applied for and received a Consortium Intramural Research Grant to fund “Creating Evidence Based Public Health Guidance for Manganese Levels in Drinking Water.” Consortium Intramural Research Awards are designed to support projects like theirs that explore the societal implications of problems in health, environment, and the life sciences. The study’s collaborative work also depends on MDH staff and other University faculty.*

Georgieff is also director of the Center for Neurobehavioral Development (CNBD), a Consortium on Law and Values member, and a world expert on the impact of micronutrients on brain development. His lab can evaluate an infant’s brain function through non-invasive tests that measure electrical fluctuations in the brain in response to stimuli, determining a child’s “event-related potential.”

To determine how to best measure and manage manganese exposure levels in prenatal women and infants, McGovern and Georgieff are working with a Minneapolis community clinic in an area with particularly high levels of manganese in the tap water. That clinic will enroll women in the study and maternal and child nurses from the Minnesota Visiting Nurse Agency will make home visits to collect data. Funds from the Consortium award will go to pay the mothers, the nurses, the biochemists doing the lab work, and for other essential people, services, and supplies. 

McGovern and Georgieff hope that their work may lead to ways to protect pregnant women and young children, like introducing filters at the tap or really promoting breastfeeding for mothers at risk, from high manganese levels. “Several studies have been done on school-aged children to look at attention deficits or other behavioral issues associated with too much manganese and other risk factors,” says McGovern. “We’re interested in studying infants because then you have the potential to prevent problems before they start.”

*Dr. McGovern’s study team includes Irina Stepanov, assistant professor, School of Public Health, and a chemist with expertise in biomarker development and analysis; Tim Church, professor, School of Public Health and a biostatician and epidemiologist; Donna Coetzee, an environmental health sciences graduate student; and Ani Rao, an MPH applicant.

Dr. Georgieff’s study team includes neonatologist Raghu Rao, associate professor of pediatrics, whose work addresses brain metabolism; Neely Miller, a research coordinator with experience in event-related potential; Michael Schmidt, CNBD associate program director; and Michael Aschner, a neurobiologist at Albert Einstein College of Medicine known for his research on the effect of heavy metals on the brain.

MDH staff include Pam Shubat, director; Kate Sande, Toxicologist/Risk Assessor; David Bell, MSResearch Scientist from the Health Risk Assessment Unit; hydrologists James Lundy and Richard Soule from the Source Water Protection Program; and Rita Messing, supervisor, Site Assessment and Consultation Unit.