The Environmental Protection Agency temporarily barred journalists and the public from a national summit Tuesday addressing toxic chemicals contamination in drinking water, a week after top agency officials’ effort to delay publication of a study on those chemicals came to light.

EPA later reversed course and said it would allow reporters to attend the afternoon sessions of the summit, three hours after initially ejecting the media. But that didn’t reassure activists from the communities that have been exposed to the chemicals, known as PFAS, who were allowed little access to the summit.

The White House plans to “look into the matter,” press secretary Sarah Huckabee Sanders told reporters at the briefing later Tuesday.

But activists from the communities that have been exposed to the chemicals, known as PFAS, were still granted little access to the summit.

“Last week, we learned that the EPA suppressed a PFAS study,” Kristen Mello, co-founder of Westfield Residents Advocating For Themselves in Westfield, Mass, said in statement. “This week, they’re convening a summit on PFAS, and, out of millions affected, only one of us is allowed to attend on only one day to bear witness. How are we supposed to trust anything about this?”

Administrator Scott Pruitt opened the two-day summit at the EPA headquarters by calling the issue one of his top priorities.

Pruitt said the agency would start a process to decide whether it should set legal limits on the concentration in drinking water of two of the chemicals, which were used in products like Teflon and firefighting foam and have been linked to immune disorders, thyroid disease and cancer. Those chemicals are contaminating the drinking water of at least 16 million Americans.

A small group of journalists including a POLITICO reporter were permitted to attend Pruitt’s opening remarks at the event where federal and state regulators gathered with business organizations and environmental groups. But those journalists were escorted out shortly after — and other news organizations, including The Associated Press and CNN, were barred from attending.

“While several news organizations were permitted, the EPA selectively excluded CNN and other media outlets. We understand the importance of an open and free press and we hope the EPA does, too,” a CNN spokesperson said in a statement.

The AP reported Tuesday that a senior aide to Pruitt called to apologize to its reporter, who had been physically removed from EPA headquarters.

The meeting comes after POLITICO reported that agency leadership had worked to delay a controversial study on the chemicals that would have showed the substances posed health risks to humans at far lower concentrations that EPA has said. Releasing that study, one unnamed White House official said in emails obtained by POLITICO, would be “public relations nightmare.”

One lawmaker was quick to blast EPA’s closed-door meeting.

“Our communities deserve answers, and the EPA seems to be doing everything in its control to block the public from getting them. It’s reprehensible,” said Rep. Carol Shea-Porter (D-NH).

EPA spokesman Jahan Wilcox said journalists were excluded from the meeting of about 200 people because of space constraints. However, a reporter at the scene said there were dozens of empty seats in the room.

“The leadership summit quickly reached capacity with a wide variety of stakeholders including representatives from over 40 states, territories, and tribes,” Wilcox said in a prepared statement.

The Federal Advisory Committee Act states that “any committee, board, commission, council, conference, panel, task force, or other similar group” used by an agency “in the interest of obtaining advice or recommendations” for the federal government must be open to the public.

Andrea Drinkard, an EPA communications staffer, said the meeting was at capacity and that attendees would be raising their hands to vote in a “polling system” and would not be comfortable with media in the room.

The only person in attendance at the summit representing contaminated communities was Andrea Amico from the New Hampshire group Testing for Pease. A list of groups present also indicates that no independent scientists were present, including those responsible for most of the known research about the compounds’ effects on human health.

The head of an HHS agency overseeing the controversial chemical safety assessment confirmed at the summit that the delayed study will find that the contaminants can be dangerous at much lower exposures than EPA has previously said were safe – and that report would be released soon.

“We’re committed to making sure that everybody’s on the same page about what our minimum risk levels are and what they mean,” Patrick Breysse, who directs the Agency for Toxic Substances and Disease Registry, told the panel.

Another participant on the panel, Erik Olson, the director of the Natural Resources Defense Council’s health program, said the report “really needs to be in the public domain.”

“It may be a draft but virtually everyone in this room I’m sure has read the press coverage of it. This really deserves to be out in the public. We need to allow people to see it. It just creates suspicion to not be releasing it,” he said.

Olson said told POLITICO earlier this week that keeping media away had increased his skepticism of Pruitt’s motives and those of other officials like Nancy Beck, who worked for the American Chemistry Council, an industry trade group, before Pruitt hired her as EPA’s deputy assistant administrator for EPA’s Office of Chemical Safety.

“I find it hard to believe that Scott Pruitt, Nancy Beck and the EPA management have suddenly realized that PFAS are a big problem and are actually planning to take meaningful action,” Olson said in an email. “This concern is reinforced by their refusal to let the press into most of the meeting, and failure to allow those most affected by PFAS contamination (people with tap water contamination, firefighters, etc.) into the meeting.”