MINNEAPOLIS — The state of Minnesota has pulled out of a research project on mercury pollution in the St. Louis River on the Iron Range.

The decision is a disappointment to the Fond du Lac Band of Chippewa and federal regulators.

Mercury contamination has made much of the river’s fish inedible for children and young women. One in 10 infants on Lake Superior’s North Shore have unsafe levels of mercury in their blood.

Minnesota Pollution Control Agency officials say the state first needs more research on how mercury behaves in nature and why levels are much higher in St. Louis River fish than elsewhere.

Others with a stake in cleaning up the river have asked the U.S. EPA to hold a public meeting on the state’s withdrawal.