A study by Mark Z. Jacobson, associate professor of civil and environmental engineering at Stanford University says that Ethanol vehicles pose a significant risk to human health.

''Ethanol is being promoted as a clean and renewable fuel that will reduce global warming and air pollution, but our results show that a high blend of ethanol poses an equal or greater risk to public health than gasoline, which already causes significant health damage." says Jacobson. For the study, Jacobson used a sophisticated computer model to simulate air quality in the year 2020, when ethanol-fueled vehicles are expected to be widely available in the United States. The study is based on cars using E85, a popular blend of 85% ethanol and 15 percent gasoline.

His findings are published in the April 18 online edition of the journal Environmental Science & Technology (ES&T).
Via Stanford University. See also Wikipedia about the background on Ethanol Fuel.