Fish study raises red flag on water supply
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Fish caught in the rivers near Allegheny County's storm sewer overflow pipes contain almost twice as much of certain estrogenic chemicals that can cause cancer, a University of Pittsburgh study has found.
The link between sewage plant discharges and fish contaminated with those chemicals has been established by studies in other urban areas around the world, but the finding is particularly significant in Allegheny County, which has more than 400 sanitary and combined sewer overflows.
The findings are a concern for public health because of the region's dependency on the rivers for its drinking water. Dr. Conrad Dan Volz, head of the study, said a number of reports have shown a link between high ingestion of estrogens and hormone problems and some cancers, including testicular cancer.
Estrogenic chemicals, called xenoestrogens or estrogen-mimicking chemicals, come from garden pesticides, plasticizers, glues, cosmetics and products that dissolve detergents. Pharmaceutical estrogens from female hormone replacement drugs and birth control pills are also found in sewage discharges.
"Pittsburgh has more combined sewer overflows than any other city in the United States," said Dr. Volz, an assistant professor in Pitt's Graduate School of Public Health. "During the summer such discharges can occur on as much as 75 percent of the days, and the raw sewage has more estrogenic chemicals that do not get broken down at all by the waste treatment process."
The latest results of the ongoing study by Dr. Volz, who is also a co-director of the Pitt Cancer Institute's Center for Environmental Oncology, will be discussed today at an institute retreat in Greensburg.
Earlier reports of study results showed that it was difficult to identify the gender of 85 percent of the channel catfish caught on the Allegheny, Monongahela and Ohio rivers near the Point, and also that chemicals extracted from all 25 randomly sampled fish caused growth of estrogen-sensitive breast cancer cells cultured in a laboratory. Eleven of those samples produced very aggressive cancer growth.
Dr. Volz has called those fish the "canary in the coal mine" for public health related to drinking water, most of which comes from the rivers in Allegheny County. The U.S. Environmental Protection Agency does not require that drinking water be tested for estrogen, or that the hormone be removed.
Nancy Barylak, a spokeswoman for the Allegheny County Sanitary Authority, said it does not test discharges for estrogen or estrogen-mimicking chemicals and isn't required to by state or federal law.
The state Fish and Boat commission has a long-standing advisory against eating any catfish from the Ohio and Monongahela rivers, and recommends consumption of catfish from the Allegheny River be limited to once a month.
First Published June 20, 2007 11:36 pm