President Trump is under fire for falsely claiming that windmills cause cancer. Trump made the remark in a speech to the National Republican Congressional Committee Tuesday, where he touted U.S. oil and gas drilling while mocking renewable energy.

President Donald Trump: “If you have a windmill anywhere near your house, congratulations. Your house just went down 75% in value. And they say the noise causes cancer. You told me that one, OK? Whirr! Whirr!”

On Wednesday, Iowa Republican Senator Chuck Grassley called Trump’s remark “idiotic,” adding, “I wish his staff would tell him I’m the father and now the grandfather of wind energy tax credits.”