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September 7, 2006


[Rachel's introduction: The cleanup of the Potomac River has long
been considered one of the nation's great success stories. Ever since
Lady Bird Johnson made it a priority in the 1960s, the Potomac has
been getting cleaner. Now, new evidence indicates that perhaps we
were measuring success incorrectly.]

By Deborah Zabarenko, Environment Correspondent

Washington -- The discovery of intersex fish -- males with some female
characteristics, including some carrying eggs -- in Washington's
Potomac River is raising concerns about pollution from chemicals that
can affect hormones.

A preliminary investigation by the U.S. Geological Survey found a high
incidence of intersex among smallmouth bass in the South Branch of the
Potomac and Shenandoah Rivers, both near Washington.

"We ended up identifying a problem that is typical of endocrine
disruption, that is, seeing eggs in the testes of sexually mature
fish," Chris Ottinger, an immunologist at the Geological Survey's
National Fish Health Research Laboratory, said on Thursday. "It was
something that warranted further investigation."

These so-called endocrine disrupting chemicals are used widely in
industry and in consumer products including pharmaceuticals,
cosmetics, perfumes, plastics and even materials used to keep
barnacles from clinging to boat bottoms.

Theo Colburn, an environmental health analyst who has specialized in
studying the effects of endocrine disruptors, said they work during
gestation, and have been linked to feminization of male fish in the
Great Lakes, smaller penises in alligators and polar bears, and
hermaphroditic whales -- with genitalia of both sexes -- in the St.
Lawrence River.

Safe To Drink

Laboratory studies have shown developmental effects from very low
doses of hormone disruptors, but it would be technically impossible at
present to remove such low concentrations of these compounds from
drinking water, Colburn said by telephone from her office in Colorado.

The manager of the water utility that covers a large swath of the
Washington area stressed that drinking water is safe.

"As water plant manager, what I know is that there is no evidence
pointing to any concentrations of these substances in the water that
are having human effects," said Thomas Jacobus, manager of the
Washington Aqueduct. "The water is safe to drink."

Jacobus said the water was tested for some endocrine disrupting
chemicals, but noted that there are potentially 20,000 of these
compounds in existence.

The U.S. Environmental Protection Agency said in a statement that the
exact amounts of these chemicals, especially at extremely low doses,
in the environment are difficult to determine.

"Little is known about the potential harm posed by trace amounts of
PPCPs (pharmaceuticals and personal care products) in drinking water,"
the agency said in a statement. "Current water treatment processes may
remove some PPCPs, but more research is needed to determine how
efficiently these compounds are removed by various treatment

Copyright 2006 Reuters Limited