By Miranda Green and Sophie Tatum, CNN

(CNN) -- Environmental Protection Agency Administrator Scott Pruitt says scientists who sit on EPA advisory boards and committees who have also received federal grants for studies could be cut from their roles as soon as next week, citing a lack of objectivity in their research.

Speaking at a Heritage Foundation event on Tuesday, Pruitt said that scientists who serve on those advisory boards who have also received funding from the EPA may not be "objective."

"There are dozens and dozens of these folks. Over the years these individuals, as they've served in those capacities, guess what's also happened? They've received monies through grants, and often substantial monies through grants," he said.

Pruitt said having individuals on EPA advisory boards who have received grants from the agency raises red flags.

"That to me causes question on the independence and the veracity and the transparency of those recommendations that are coming our way," he said.

Pruitt said he would act next week to "fix that."

"I'm going to issue a directive that addresses that -- that is much like sue and settle -- to insure the independence and transparency and objectivity in regard to the scientific advice we are getting at the agency," he said.

Jennifer Sass, the Natural Resources Defense Council's health program senior scientist, said Pruitt's goal was to "get rid of scientists who tell us the facts about threats to our environment and health."

The "sue and settle" directive Pruitt referenced was a practice the agency announced it was ending on Monday.

"The days of regulation through litigation are over," Pruitt said in Monday's statement. "We will no longer go behind closed doors and use consent decrees and settlement agreements to resolve lawsuits filed against the agency by special interest groups where doing so would circumvent the regulatory process set forth by Congress. Additionally, gone are the days of routinely paying tens of thousands of dollars in attorney's fees to these groups with which we swiftly settle."

During his speech at the Heritage Foundation, Pruitt also confirmed that he's looking at a red team-blue team approach into questions about climate change.

The concept of red team-blue team is generally associated with the military and intelligence organizations to simulate security scenarios.

"The American people deserve an objective, transparent and honest discussion about what we know or don't know with respect to CO2 -- it's never taken place." Pruitt said. "And that's the reason I have been proposing a red team-blue team exercise ... where we'd bring red team scientists in and blue team scientists in and they would engage in a multi-month process asking of each other these very difficult questions to help inform the American public on these issues to help build consensus towards this very important issue."

Sierra Club Executive Director Michael Bruce also opposed Pruitt's announcement.

"Of course Scott Pruitt doesn't want to support science, because science makes clear that Pruitt's policies are disastrous for the health of our kids and our communities," Bruce said. "For Pruitt, anything that helps corporate polluters make money is good and science and facts are just roadblocks he wants to tear down."