Sen. Chuck Grassley (R-Iowa) publicly rebuked President Donald Trump‘s unsubstantiated claim that wind turbines are linked to cancer, calling it “idiotic.”

Trump, who has long attacked wind power and frequently fought against wind turbines being built near the golf courses he owns, made the claim at a Republican fundraising event on Tuesday.

“If you have a windmill anywhere near your house, congratulations. Your house just went down 75 percent in value,” he claimed. “They say the noise causes cancer.”

“I wish his staff would tell him I’m the father and now the grandfather of wind energy tax credits. I don’t think he knows it or I don’t think he’d make those comments that aren’t quite appropriate,” said Grassley, who authored the Wind Energy Incentives Act of 1993.

The longtime Iowa GOP senator said Trump’s cancer claim, which has no factual basis, was probably “tongue in cheek.”

He also said he was more experienced with the energy crisis of the 1970s and has to teach the majority of the new politicians about wind energy, including the president.

“I’ve lived through it, he never has. So, I’m going to give him some leeway when he criticizes alternative energy. Because I’ve gotta do it with 85 percent of the people that are new since we developed all of this. And they think it’s stupid that we have wind and solar and everything else, except for a few progressives,” Grassley said. “I’m not a progressive but I’m in favor of alternative energy.”

Scientific studies have found no evidence that wind turbines directly cause any human health risks.

Some Republicans, however, have avoided directly challenging Trump’s assertion. Gov. Kim Reynolds (R-Iowa) said it “wasn’t her place” to decide whether wind turbines cause cancer. “You know how those things change. One year, coffee’s good for you. The next year, coffee causes cancer.”