AUGUSTA, Maine (AP) Maine lawmakers want to strengthen lead testing in school drinking water.

The Maine Legislature has been considering a proposal to decrease the standard for lead in drinking water from 15 parts per billion to four parts per billion. The Maine House of Representatives unanimously approved of the proposal on June 7 and sent it to Democratic Gov. Janet Mills.

Lead exposure in children has been linked to slowed growth, hearing problems, anemia and other health problems. Rep. Michele Meyer, the bill’s sponsor and a Democrat, said lead is “dangerous at all levels” and the state must “substantially lower the levels of lead in our students’ drinking water.”

Supporters of the proposal cited a 2018 report from the Maine Department of Health and Human Services that called lead poisoning “one of the major environmental health threats for children in Maine.” The report said nearly 400 children were identified as suffering lead poisoning in 2017.