Ethanol Has Drawbacks

By Anonymous

Ethanol may not be the healthiest solution to the atmospheric pollution problem after all, according to a recent study from Stanford University. A computer model simulated U.S. air quality in 2020, when ethanol-fueled vehicles are expected to be widely available. “Ethanol is being promoted as a clean and renewable fuel that will reduce global warming and air pollution,” says Mark Z. Jacobson, author of the study. “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.” Many factors influence the exact blend of chemicals in car emissions, including chemical reactions, temperatures, sunlight, clouds, wind, and precipitation. “In addition, overall health effects depend on exposure to these airborne chemicals, which varies from region to region. Ours is the first ethanol study that takes into account population distribution and the complex environmental interactions,” Jacobson explains.

The model tested two future sce-narios: a vehicle fleet fueled by gasoline and a fleet powered by E85, the popular blend of 85 percent ethanol and 15 percent gasoline. The E85 vehicles reduced levels of two carcinogenic pollutants, benzene and butadiene. However, it increased levels of two other carcinogens, formaldehyde and acetaldehyde. “As a result, cancer rates for E85 are likely to be similar to those for gaso-line,” Jacobson says.

In some parts of the country, E85 appeared to raise ozone levels significantly. Inhaling ozone can decrease lung capacity, inflame lung tissue, exacerbate asthma, and impair the body’s immune system. “In our study, E85 increased ozone-related mortalities in the United States by about 200 deaths per year compared to gasoline,” Jacobson says. Additionally, Jacobson notes that the deleterious health effects would be the same if the ethanol were made from switchgrass or any other plant product.

“There are alternatives, such as battery electric, plug-in- hybrid, and hydrogen fuel cell vehicles, whose energy can be derived from wind or solar power,” he adds. “These vehicles produce virtually no toxic emissions or greenhouse gases and cause very little disruption to the land-unlike ethanol made from corn or switchgrass, which will require millions of acres of farmland to massproduce.”

-Stanford University press release, 18 April. (M.H.P.)

Copyright Heldref Publications Jun 2007

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