Environmental Protection Agency Administrator Scott Pruitt said Tuesday that removing hazardous chemicals from contaminated water supplies is a “national priority,” even as he sought to downplay his agency’s role in burying a critical study on the dangers of these chemicals.

“It’s clear this issue is a national priority we need to focus on as a country,” Pruitt said at the opening of a two-day summit meeting Tuesday morning with state, local, tribal, industry, and nonprofit officials at EPA headquarters.

Pruitt’s call for action comes after emails produced by a Freedom of Information Act request showed the EPA and the White House tried to block publication of a federal study of a toxic chemical class known as known as per-poly fluorinated chemicals, or PFAS, that has been linked with thyroid defects, problems in pregnancy, and certain cancers.

[Related: Arnold Schwarzenegger: Scott Pruitt should drink contaminated water until he taps out or resigns]

The White House reached out to the EPA fearing a “public relations nightmare” if the study was released, and the emails indicate EPA officials agreed to slow down the release by suggesting an “interagency review”, Politico reported.

Pruitt on Monday night downplayed his agency’s role in burying the study, which found PFAS that have contaminated water supplies are harmful to human health at lower levels than the EPA previously deemed safe.

"EPA does not have the authority to release this study,” Pruitt said in a letter obtained by the Washington Examiner that was sent to Rep. Dan Kildee, D-Mich., who asked the EPA to release the study.

Some Republican lawmakers including Rep. Mike Turner of Ohio and Brian Fitzpatrick of Pennsylvania also have demanded answers about why the study has not been released.

Pruitt said the Department of Health and Human Services, which prepared the study, has the authority to release it. He told a Senate Appropriations subcommittee last week that he “was not aware that there had been some holding back of the report.”

The study, conducted by the Centers for Disease Control, said the EPA’s benchmark for PFAS, at 70 parts per trillion, is six times higher than what it should be. It also said exposure to PFAS in drinking levels at just 12 parts per trillion can be dangerous.

The stain-resistant chemicals have been used since the 1940s in Teflon, nonstick pans, electronics, water-repellent clothes, and firefighting foam.

An analysis published Tuesday by the Environmental Working Group found that up to 110 million U.S. residents may be exposed to drinking water contaminated with PFAS.

Michigan is planning to spend $1.7 million to test water supplies across the state, including in 1,380 public water systems and 461 schools. Communities in New York, West Virginia, North Carolina and other states also have found the chemicals in their drinking water.

As Pruitt sought to deflect responsibility for releasing the study, he tried to assure state and local officials that he takes the issue seriously. At the summit meeting, he said the chemicals have “helped save lives” but acknowledged “concerns” about them tainting the environment in an “adverse way.”

Pruitt promised that EPA is working to declare PFAS a “hazardous substance.” He said the agency is developing an updated determination on the maximum level of PFAS in groundwater that is considered safe and is drafting a National PFAS Management Plan, slated for release this fall.

Agency officials will travel to states and communities affected by contamination beginning next month, he said.

Reporters were asked to leave the the day-and-half long summit meeting after an hour on Tuesday, and public access was blocked, sparking criticism from environmental groups. Victims of PFAS exposure from affected communities were also not invited to the summit.