Minnesota’s top health and environmental officials sent a blistering letter Wednesday to the U.S. Environmental Protection Agency, charging that its controversial plan to impose broad new restrictions on the types of scientific research it uses to craft regulations will cause confusion, mistrust and “threaten the lives of real people.”

“EPA should withdraw this dangerous proposal,” wrote John Linc Stine, commissioner of the Minnesota Pollution Control Agency and Jan Malcolm, state health commissioner.

It is the most forceful public criticism that Minnesota officials have issued since Administrator Scott Pruitt began imposing sweeping reversals of long-held EPA regulatory policies. Stine characterized the letter as “speaking truth” to the agency.

An EPA spokesperson did not comment on the letter but said the agency welcomes public comment.

Last month Pruitt proposed a dramatic policy shift that would restrict the EPA to using only scientific studies that contain publicly available data — data that industry and the public would be free to examine. In announcing it at a private meeting with a conservative news outlet, Pruitt said his goal was to improve the transparency of significant regulations.

“The era of secret science at EPA is coming to an end,” Pruitt said in a news release at the time. “Americans deserve to assess the legitimacy of the science underpinning EPA decisions that may impact their lives.”

The proposal, however, triggered alarm among academic and public health researchers, who said it would have the effect of ruling out much of the most important environmental research conducted across the country — and noted that it echoed a tactic proposed years ago by the tobacco industry.

Many scientists say Pruitt’s rule would exclude much of the major medical and epidemiological research that in the past led to important regulations covering mercury, lead, air pollution and other toxins. That’s because such studies rely on the compilation of medical data from thousands of individuals over time. When participants agree to participate in such studies — the bedrock of public and environmental health research — they are promised that their records will remain confidential.

Officials said Wednesday that some of Minnesota’s most critical public health and environmental protections in force today were based on studies that would be excluded under the proposed rule. The high level of mercury found in newborns along the North Shore of Lake Superior, for example, was based on umbilical cord blood tests from babies born around the Great Lakes, and would be the kind of study used to determine regulations for mercury, Stine said.

Studies involving residents of Cottage Grove and Oakdale helped establish the state’s latest health recommendation for PFCs in drinking water, and could be included in the body of science for new federal standards that are underway.

The rule would also exclude health surveillance data, which public health agencies such as the Minnesota Department of Health collect on a myriad diseases from patients at hospitals and doctors offices.

“That largely relies on the public having faith and confidence in our ability to protect their information,” assistant health Commissioner Paul Allwood said.

The proposed rule, which is now in a 30-day public comment period, includes a number of caveats: It does not compel the release of private information; the EPA administrator can make exceptions; and private data could be redacted when possible. But critics say that reviewing voluminous studies to pinpoint and redact private data would be hugely expensive at a time when the EPA is facing budget cuts. In addition, they said such redactions are not always foolproof, and that the risk and added burdens would dissuade researchers from conducting such research or sharing it.

Restrictions of the kind Pruitt proposed have long been supported by some industries and conservative members of Congress. The phrase “secret science” was first coined by consultants for the tobacco industry, who were trying to challenge the research demonstrating the health impacts of smoking. The proposed rule is a near copy of legislation in the U.S. House supported by the oil and gas industry in connection with air quality rules.

In its public comment on the proposed rule, the National Federation of Independent Businesses, which represents small businesses, urged the EPA to go even further by making the underlying work available at the earliest possible point in the research, and to make any exemptions public as well.

Scientists, public health and environmental advocates have risen up in protest, saying the intent is to inject doubt and politics into the scientific process and weaken protections.

Stine and Malcolm agree.

“[We] are appalled by the specious and brazen attack on health sciences research and the field of epidemiology,” they wrote. “The proposed rule was clearly designed to undermine and disparage the important epidemiological studies that support public health protection from all pollutants, be they in the air, water, or soil.”

In an interview Wednesday, Stine and Allwood also said validity of such research is already ensured by institutional review boards, which approve studies before they begin, and by peer review before they are published.

“It really is a bit of red herring to suggest that scientists are using methods that are not considered credible,” Stine said.

Allwood said that if the EPA adopts the new rule, its evaluation of health risks would most likely have to rely on studies using animals in laboratory settings, instead of those using health data from people who are exposed to contaminants in real, long-term situations.

The proposed rule has also drawn criticism from the National Academy of Sciences, which advises the federal government on scientific matters. “Excluding relevant studies simply because they do not meet rigid transparency standards will adversely affect decisionmaking processes,” the organization said in a recent statement.

Read the letter: