Watchdog groups are calling the intersex condition in fish a "canary in the coal mine" for metropolitan drinking water supplies.

This week the Potomac Conservancy released its third annual "State of the Nation's River" report.    The report raised attention about various pollutants within the Potomac watershed.   The most notable of the contaminants were endocrine disruptors.   The reports claims the endocrine disruptors can have negative impacts on growth and sexual development on many vertebrate species--specifically fish and humans.  

“Endocrine disrupting compounds are major pollutants in the Potomac watershed, and we need to exercise the utmost caution when introducing these compounds into our rivers, streams and, ultimately, our drinking water,” said Dr. John Peterson “Pete” Myers, chief scientist for Environmental Health Sciences of Charlottesville, Virginia.

The contaminants are blamed by many for the condition of intersex found in the South Branch of the Potomac River smallmouth bass and in many black bass species across the country.   A recent study by the US Fish and Wildlife Service revealed the problem was far more widespread across the country than previously believed.    

What's been harder to prove, at least in the waters of the upper Potomac in West Virginia, is the main source.  Endocrine disruptors are found in a host of everyday products including pharmaceuticals, pesticides, veterinary products, and personal care items.    

The report also included a call to action to press Congress for amending the Safe Drinking Water Act to add endocrine disruptors to the list of contaminants treated in municipal water plants.  Currently, they are not targeted in the water treatment process.

“Water treatment facilities are not yet required to screen for endocrine disrupting contaminants, so they end up in our tap water,” Myers said. “We aren’t sure exactly what level of exposure causes harmful effects to human health, but if the intersex fish phenomenon is any indication, there’s a critical need for regulatory agencies and decision makers to start addressing this issue.”

The intersex condition was first noticed in West Virginia's Potomac River fisheries in the 1990s when male smallmouth bass were fond to have female characteristics, even having eggs developing within their system.    So far biologists from the West Virginia DNR say the problem has not reached a level to adversely impact fish reproduction in the river.