WASHINGTON, D.C., Nov. 7 - Emissions from coal-fired power plants may be an important source of water pollution and fish contamination, say researchers at the University of Pittsburgh Graduate School of Public Health in a study being presented at the annual meeting of the American Public Health Association in Washington, D.C. The study, abstract number 157770, found higher-than-Environmental Protection Agency (EPA)-recommended levels of mercury and elevated levels of selenium in channel catfish caught in a rural area upstream of Pittsburgh and downwind from a coal-fired power plant. Both mercury and selenium are well-known contaminants of coal burning for power generation. The results will be presented at a special session on "Contaminants in Freshwater Fish: Toxicity, Sources and Risk Communication," at 8:30 a.m., Wednesday, Nov. 7.
To complete the study, researchers recruited local anglers to catch channel catfish from the three rivers area of Pittsburgh and from Kittanning, Pa., an area 40 miles upstream of Pittsburgh. The three rivers area includes the Allegheny, Monongahela and Ohio rivers. Based on testing of 63 fish, they found that Kittanning and three rivers area fish had 19 and 3.1 times more mercury, respectively, than store-bought fish. They also found significantly higher levels of mercury and selenium in the Kittanning-caught fish than in the fish caught in the three rivers area.
Results showed that the risk of developing neurological disorders from ingesting catfish with such high levels of mercury as those caught near Kittanning were eight times higher than the EPA's acceptable risk for children under six years of age; seven times higher for children between seven and 16 years of age; and six times higher for women of child-bearing age. For the general population, this risk was five times higher than the EPA's acceptable risk. The results also indicated to the researchers that fish can be used as bio-sensors to locate and find sources of area pollution.
"Given these results, we should be concerned about fish caught in areas that are situated close to coal-fired power plants, even if upstream from more heavily polluted areas," said Conrad D. Volz, Dr.P.H., M.P.H., principal investigator, department of environmental and occupational health, University of Pittsburgh Graduate School of Public Health. "These types of power plants may be significant sources of mercury and selenium in fish contamination. We believe it is important for fish consumption advisories to take into account industries such as power plants that may be important sources of water pollution, and warn people in these areas about the dangers of consuming local fish."
Ingestion of fish with high levels of mercury has been linked to neurological and developmental problems and birth defects.
The study was funded by grants from the Highmark Foundation, the DSF Charitable Trust and the Heinz Endowments. Co-authors include Yan Liu, Nancy Sussman, Ph.D., Tiffany Green, Jim Peterson, Ph.D., Charles Christen, Maryann Donovan, Ph.D., Devra Davis, Ph.D., Patricia Eagon, Ph.D., Kelly McMahon, M.D., and Ravi Sharma, Ph.D., all with the University of Pittsburgh; Sean Brady, Venture Outdoors, Pittsburgh; Paul Caruso, channel catfish angler; and Myron Arnowitt, Clean Water Action, Pittsburgh.