New pollutants threaten area waters

New pollutants harming fish; are they a threat to humans, too?

Date published: 11/12/2009

By RUSTY DENNEN

New pollutants brewing in the Potomac River basin are creating fish with both male and female characteristics, and may be playing a role in fish kills.

As a result, more regulation of new chemicals is needed, along with study of the potential effects of "endocrine disrupters" on humans who are drinking the water.

Those are a few of the findings the Potomac Conservancy's State of the Nation's River report, released yesterday in a conference call with reporters.

The report, in its third year, focuses on the troubling discovery of intersex fish--mostly smallmouth bass--in the Potomac and Shenandoah rivers in Virginia and the Monocacy River in Maryland.

Vicki Blazer, a fish pathologist with the U.S. Geological Survey, was among scientists looking into fish kills in 2002 when male fish with eggs and female fish with reduced reproductive function turned up in the research.

"Since that finding, we've worked with West Virginia, Virginia and Maryland to address fish kills and intersex fish. More and more, as we look at it, both are associated."

She said that intersex fish also tend to have diminished immune systems, but she said that's not the whole picture.

"It is just one of the indicators, and the one that has attracted a lot of public attention. I don't believe we're going to find just one chemical or one source. What we're seeing is complex mixtures," Blazer said.

The contaminants enter waterways in the form of pesticides and fertilizers, industrial byproducts, agricultural and veterinary products, pharmaceuticals, per- sonal-care products and biosolids.

John Peterson Myers, chief scientist with Environmental Health Services in Charlottesville and co-author of a book on the subject, "Our Stolen Future," said the problem extends beyond fish and aquatic life.

"To put it in a broader context, first, it is clear that the patterns of contamination are important for wildlife," he said. Research is showing how "contamination, even at remarkably low levels, affect wildlife and is likely to be affecting people." That's significant because 90 percent of those living in the Washington area get their drinking water from the Potomac.

Plants that treat wastewater and filter drinking water are currently not removing many of the contaminants from water intakes or discharges into the river, the conservancy says.

Vicki Blazer, a fish pathologist with the U.S. Geological Survey, says stemming endocrine disrupters is not just the responsibility of industry and regulators. "People use these every day on their lawns, in their homes, and a lot are simply not aware of the changes they could make." The Potomac Conservancy has some recommendations, including: Don't flush unneeded or expired medications down a toilet or drain. Unused personal-care products are best disposed of in a landfill. If medications must be thrown away, leave them in their original container to reduce seepage at the landfill. Consider using products with biodegradable ingredients that are less likely to harm the environment. There are many sources of contaminated water: municipal wastewater treatment plants, on-site waste disposal facilities, hospitals, livestock, and poultry and fish production facilities. Contamination continues in smaller concentrations via runoff from impervious surfaces (i.e. rocks) and contaminated sediment, including runoff from areas where treated water and/or residual biosolids from wastewater treatment are applied.

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Date published: 11/12/2009

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