Switching the nation's vehicles from gasoline to mostly ethanol will not reduce air pollution, a new study finds. The work joins other evidence questioning the benefits of ethanol fuel.
Mark Z. Jacobson, an atmospheric scientist at Stanford University, created a model that takes into account how the chemicals emitted in car exhaust transform through reactions in the atmosphere. He combined the resulting chemical profile with population and health-effects data to determine the risks associated with each of the fuels.
Jacobson looked at emissions from E85, the 85 percent ethanol, 15 percent gasoline blend considered a potentially large-scale replacement for gasoline. He examined a scenario based on expected emissions in 2020, the first year that he says that E85-ready cars might dominate the roads.
Jacobson's calculations predicted health effects in response to ozone and carcinogens attributable to an all-gasoline fleet or an all-E85 fleet. He found that E85 use may