Geo-microbiologist Eva Sedo is focusing the search on members of a bacterial family known as the "sulfate-reducing bacteria" group. Researchers know that many sulfate-reducing bacterial species can produce methylmercury - the form of mercury most likely to contaminate fish - but it's still unclear which species produce the greatest amounts of the toxin.

Sedo says strategies to prevent mercury contamination will be limited unless scientists gain a deeper understanding of the sulfate-reducing bacterial community. She hopes to further that understanding by studying organisms in the Florida Everglades and in northwestern Ontario, Canada. Sedo has collected dozens of sulfate-reducing species from those sites to gauge how much methylmercury each is able to produce.

CONTACT: Eva Sedo, (608) 217-3190, sedo@wisc.edu

Consequences of exposure to methylmercury during development:
Tuesday, Aug. 8, 10 a.m., Grand Terrace: Pregnant rats that were exposed to a potent form of mercury gave birth to offspring that later showed problems changing their behavior to adjust to changes in their environment. A diet of fish oil - which some people think might counteract these consequences of methylmercury exposure - did not help the rats overcome their behavioral problems as they aged.

Elliott Paletz, a researcher with the UW-Madison Department of Psychiatry, tested the long-term consequences of in utero exposure to methylmercury, a common and highly toxic form of the metal. Exposure to methylmercury during development is known to cause serious neural and behavioral problems for many animals later in life.

Paletz says adult rats that had been exposed to methylmercury in utero were able to learn specific tasks - for example, pushing a lever when a light was turned on when they received food as a reward. However, the
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Contact: Kathleen Schmitt
media@mercury2006.org
608-262-6393
University of Wisconsin-Madison
3-Aug-2006