A recent study from the Environmental
Science and Technology journal raises
some new concerns about ethanol-based E85 (85% ethanol, 15% gasoline) which
can be used in automobiles. The study finds that if much of the country's fuel
supply would switch from gasoline to E85, the number of deaths from respiratory
failure (due to ozone) in the United States would rise from 4,700 people a year
to nearly 4,900 per year.
"It's not green in terms of air pollution," said
study author Mark Jacobson, a Stanford University environmental engineering
professor and author of the study. "If you want to use ethanol, fine, but
don't do it based on health grounds. It's no better than gasoline, apparently
Jacobson used computer models to determine the effects of an
increased use of ethanol in automobiles and how they would impact air pollution.
The models determined than an increased reliance on E85 would result in
increased smog levels -- especially in Los Angeles and major cities in the
Jacobson contends that the increase in smog levels is due to
the fact that more hydrocarbons are released into the atmosphere from the
combustion of ethanol than from gasoline. Jacobson also notes that ethanol
produces less nitrogen oxide which most often is a positive side effect.
However, in smog-filled areas like Los Angeles the decreased nitrogen oxide
levels can be harmful to the atmosphere.
Matt Hartwig, a spokesman for the Renewable Fuels
Association, says that he respect's Jacobson's work but takes issues with some
of his findings and methodology. Hartwing notes that when using real-world data
instead of computer models "ethanol is a greener fuel than gasoline."
President Bush laid out plans earlier
this month for the United States to reduce its dependency on gasoline.
"We have laid out a plan that will affect greenhouse gases that come from
automobiles by having a mandatory fuel standard that insists on 35 -- using 35
billion gallons of alternative fuels by 2017, which will reduce our gasoline
uses by 20 percent and halt the growth in greenhouse gases that emanate from
automobiles," said President Bush.
Bush's plan would require that auto manufacturers dedicate
more of their resources into producing more E85-capable, hydrogen fuel-cell,
Brazil uses sugar cane as the
main component for ethanol used in automotive applications. Brazil is also
the largest producer of ethanol as a fuel and nearly half of the vehicles
running in the country are powered by ethanol. The United States uses corn
instead of sugar cane to produce E85 fuel. Less than 3 percent of new vehicles
available for purchase in the United States can run on E85.