In Oregon’s recent rulemaking to make the state’s toxic criteria the most stringent in the country, the Department of Environmental Quality (DEQ) also sought to remove its water quality standards for iron and manganese. DEQ told its advisory committee repeatedly that the only concerns with iron and manganese involved laundry staining.

Contrary to DEQ’s representations, there are both human health and aquatic life concerns with regard to iron and manganese. For example, it turns out that iron is hazardous to fish as is manganese. And manganese is hazardous to people. It turns out that EPA has been updating its information on the hazards of manganese over the years, information that apparently DEQ didn’t even bother to consider, even as it complained that its manganese criteria was based on EPA’s work in 1976.

Of particular interest is information on the effects of manganese on infants. According to the Environmental Working Group, manganese is a neurotoxic chemical found in soy-based infant formula at levels 80 times more than in mother’s milk. Studies show an association between various learning or behavior problems and elevated manganese levels and infants are not able to excrete excess manganese.

As NWEA points out in a letter to EPA  combining high levels of manganese in infant formula with manganese in drinking water could result in a health threat to infants. EPA’s addressing this concern would be consistent with the 1997 Executive Order on Protection of Children from Environmental Health Risks and Safety Risks.