Arnold Schwarzenegger tweeted a jab at Environmental Protection Agency (EPA) Administrator Scott Pruitt on Wednesday after reports that the EPA intervened to stop the publication of a federal study that would have set stricter levels for toxic chemicals in drinking water.

“I’m a simple guy so I have a simple remedy when people like Pruitt ignore or hide pollution: if you don’t have a problem with Americans drinking contaminated drinking water, drink it yourself until you tap out or resign,” Schwarzenegger tweeted.

The former California governor’s suggestion follows the release of internal Trump administration emails this week that showed EPA officials were concerned about a public relations “nightmare” that could stem from another agency’s expected plans to strengthen standards for fluorinated chemicals in water.

Their suggestion would set safe levels for the chemicals at almost one-sixth of the EPA’s current suggested standard. Politico first reported on the emails on Monday.

Fluorinated chemicals are used in products like hoses to reduce emissions for vehicles and stain resistance for clothing, but are also associated with major health risks including kidney and testicular cancer.

Pruitt is facing several probes for a number of ethics issues, including his use of first-class travel, his rental of a condo co-owned by the wife of a then-energy lobbyist and his use of private email accounts for official EPA business. He is already under pressure to resign from some critics because of those issues.

Pruitt, testifying before senators on Wednesday, said that some of the decisions leading to the scandals were not handled properly.

“There have been decisions over the last 16 months or so that, as I look back on those decisions, I would not make the same decisions again,” he said.