CHAMPAIGN, Ill. -- Preliminary but cautiously given good news for aging Great Lakes fish-eaters: First-round tests of fine motor skills showed barely a hint that years of consuming PCB- and DDE-contaminated fish have had any negative effects.
The study, when completed, will provide a rare, comprehensive look at the effects of environmental contaminants on older people. Scientists began a neurological assessment in 1992 of a group of men and women older than age 50 who have consumed 24 or more pounds of sport-caught Lake Michigan fish annually since the 1960s. A comparable group from the same region who didn't eat fish also is being studied. The fish-eaters have elevated levels of several contaminants, including PCBs and DDE (a derivative of the pesticide DDT).
Preliminary test results of dexterity and hand steadiness were presented May 12-15 in Montreal during Health Conference '97, which was devoted to pollution of the Great Lakes Basin. An overview of the project -- funded by the Agency for Toxic Substances and Disease Registry of the U.S. Department of Health and Human Services -- was published last year in the journal Toxicology and Industrial Health.
"People eating fish in the 1960s and '70s were really getting the highest level of exposure," said principal investigator Susan L. Schantz, a professor of environmental toxicology at the University of Illinois. "PCBs and DDE are not very easily metabolized; they tend to accumulate in body fat."
Animal research has shown that PCBs (polychlorinated biphenyls) -- a group of industrial chemicals toxic in the environment -- decrease dopamine levels in the brain. In Parkinson's disease, too little dopamine contributes to a reduction of motor function and executive abilities (planning and attention).
"We thought that we might see reduced motor function," she
said. "At this point, however, it doesn't look like it. We've only
looked at two of a large number of tests that we have yet to
Contact: Jim Barlow, Life Sciences Editor
University of Illinois at Urbana-Champaign