Naturally Occurring Microbes Convert Gasoline Additive to Harmless Byproducts
Micro-organisms that live at the bottom of lakes and streams may offer a solution to the problem of drinking water contamination from the gasoline additive MTBE, according to a new study by government scientists.
In use for more than 20 years as a way to help lower carbon monoxide emissions from gasoline-powered vehicles, MTBE (methyl tert-butyl ether) has come under fire in recent years because of growing concern about its potential harmful health effects in people.
Writing in the June 1 print issue of the research journal Environmental Science & Technology, scientists with the U.S. Geological Survey in Columbia, S. C., say their study indicates that naturally occurring micro-organisms may act as a "significant barrier" to the entry of MTBE into surface water systems. The journal is published by the American Chemical Society, the world's largest scientific society. The study initially appeared April 21 on the journal's Web site.
"Our results indicate that these micro-organisms are able to degrade MTBE to nontoxic byproducts if oxygen is present in the microbial environment," says Paul Bradley, Ph.D., lead author for the study. "This finding indicates that such microbial communities serve to protect surface drinking water supplies from MTBE contamination."
Rain is the primary way that MTBE gets into surface waters. Entering the atmosphere through evaporation when people fill their gas tanks, MTBE is subsequently dissolved by rainfall and washes into streams and lakes. MTBE also can be found in ground water, but surface water is more of a concern to many people since it accounts for approximately 60 percent of municipal drinking water in the United States, says Bradley.
"This is the first time that MTBE biodegradation by naturally occurring surface
water micro-organisms has been shown," notes Bradley. Found in the bed sediments
of lakes and streams, t
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Contact: Charmayne Marsh
ycm93@acs.org
202-872-4445
American Chemical Society
4-Jun-1999