Gov. Mark Dayton will not ask the Minnesota Department of Health to conduct a separate review of human health risks from a proposed copper-nickel mine in northeastern Minnesota — an idea he had considered at the request of leading public-health authorities.

In a memo to the governor, commissioners from three lead state regulatory agencies said they agreed that such a review would delay the project’s long regulatory process without adding new scientific information and that it might make the state vulnerable to a court order voiding a massive environmental review completed just last month.

State Health Commissioner Ed Ehlinger was among several leading health authorities who had asked the Minnesota Department of Natural Resources (DNR) to conduct the review. Others included the Minnesota Nurses Association, Minnesota Public Health Association and the Minnesota Medical Association. They said the mine could release asbestos fibers, increase mercury in the region’s aquatic food chain and contaminate drinking water.

But the DNR, which led the environmental study of PolyMet Mining Corporation’s proposal, declined to conduct a separate health review, saying it had addressed the issues in the 10-year environmental-impact statement.

Dayton’s office on Monday released a memo signed by Ehlinger, DNR Commissioner Tom Landwehr and John Linc Stine, commissioner of the Pollution Control Agency. In it, they said additional study would not be useful in state decisions on permits for the project, the next phase of the regulatory process. They also said that such a review would “call into question” the completeness of the environmental-impact statement and that it “could lead a court to order” another one.

Environmental groups on Monday faulted Dayton’s decision as shortsighted. Paula Maccabee, an attorney with WaterLegacy, said the environmental review failed to adequately reflect the increased risks to pregnant women and infants who could be exposed to higher levels of mercury in fish from the region.

The commissioners said “our three agencies are deeply committed to protecting human health and the environment. … We are committed to carefully evaluating PolyMet’s proposed [project] before making any permitting decisions.”