Ethanol Could Worsen Smog, Sickness

April 18, 2007 — If President George W. Bush's Twenty in Ten Initiative works to increase renewable and alternative transportation fuels, the United States will have 35 billion gallons of ethanol at its disposal by 2017.

Sounds great. After all, alternative fuels reduce our country's dependency on foreign oil and are gentler on the environment. Right?

Maybe not. A new study shows that ethanol could pose the same or even greater health risks to humans than gasoline and does little, if anything, to make the air more breathable.

"Ethanol is a really poor solution to the climate problem and it is not a good solution for the air quality problem," said Mark Jacobson, associate professor of civil and environmental engineering at Stanford University. Jacobson reports his research in the April 18 online edition of Environmental Science and Technology.

The results are based on a comprehensive computer model that combines human population distribution and health data with complex environmental conditions, including chemical reactions, temperatures, sunlight, clouds, wind and precipitation.

Jacobson used the model to simulate two air quality cases for the year 2020 — one that showed what the air quality would look like if Americans were still driving gasoline-powered vehicles and another that illustrated air quality if everyone were driving vehicles powered by E-85, a blend of 85 percent ethanol and 15 percent gasoline.

Jacobson compared the two scenarios and found that although using ethanol, instead of gasoline, will reduce two dangerous carcinogenic emissions (benzene and butadiene), it will increase two others (formaldehyde and acetaldehyde).

Ethanol also escalates ground-level ozone, otherwise known as smog. (The same ozone located 10 to 30 miles high in the stratosphere protects the Earth from harmful ultraviolet radiation.)

A number of health studies have shown a link between increases in ground-level ozone and a rise in illnesses, hospital visits and even death. When Jacobson's computer model crunched the numbers, the results were grim: 200 more ozone-related deaths, 770 more asthma-related emergency room visits, and 990 more respiratory-related hospitalizations.

Tad Patzek, professor of geoengineering at the University of California, Berkeley, said scientists have known for years that ethanol contributes to increased emissions of smog-forming gases and vapors, but that this detailed of a study is the first of its kind to his knowledge.

"Nobody has done such a study on ethanol-related emissions on automobiles," he said.

So if ethanol is known to increase smog, why is it being touted as eco-friendly?

"A long time ago, alternative fuels were definitely cleaner than gasoline," said Mark Delucchi, a research scientist at the Institute of Transportation Studies at University of California, Davis.

But more recent improvements in emissions control are evening the playing ground between fossil and alternative fuels, he said.

"I don't think anybody can seriously put forth ethanol as a fuel that is going to improve air quality and protect human health," said Delucchi.

But ethanol is poised to do something. Already the country has more than 1,000 fueling stations nationwide and this past March, the U.S. Department of Energy announced $23 million in funding for five projects to convert biomass material to ethanol.