"There is growing evidence that when used in the summer with reformulated gasoline, ethanol actually creates more smog and fine-particle soot," said Frank O'Donnell, a longtime clean air advocate in Washington, D.C. "Ethanol has been oversold as a clean fuel."
His comments are backed by a new draft study from the California Air Resources Board, the nation's leading air pollution agency, and other reports, the Louisville (Ky.) Courier-Journal reported Thursday.
"Ethanol really doesn't do anything for fuel anymore," said Jerry Martin, a spokesman for the California air board, which has been locked in a six-year legal battle with the U.S. Environmental Protection Agency over permission to stop using an ethanol mixture.
However, advocates see ethanol as a renewable fuel made from homegrown crops like corn, and say its use can help reduce U.S. dependence on foreign oil.
Notable deaths of 2014 [PHOTOS]