[Pharmwaste] Effluent changes gender of fish

[Tenace, Laurie]

http://www.trib.com/articles/2006/12/12/news/regional/87a0a21fccb3d8a58725724
1006d1666.txt


Effluent changes gender of fish
By BOONSRI DICKINSON and TODD NEFF
Scripps Howard News Service Tuesday, December 12, 2006



In 2004, David Norris reported that fish just below the Boulder, Colo.,
Wastewater Treatment Plant's outflow pipe were changing sex.

Two years later, the University of Colorado integrative physiology professor
has expanded his study, which now involves one "Fish Exposure Mobile"
research trailer in operation and a second on the way.

Science done in the trailer has verified Norris' 2004 study and shown that
surprisingly low concentrations of treatment-plant effluent can change male
fish into females.

The 2004 study showed that certain chemicals from pharmaceuticals and
personal-care products made it through the Boulder Wastewater Treatment Plant
and into Boulder Creek. Ninety percent of the white suckers swimming
downstream of the plant were female. Upstream, there was an even split.
"What we see in the fish downstream is as if they are taking birth control
pills," Norris said.

The female fish -- both the transsexuals and the original girls -- had
smaller-than-average ovaries. The remaining males produced less sperm,
showing the water effluent also has contraceptive effects, he said.

The chemicals are believed to come from excreted birth-control hormones,
natural female hormones and detergents flushed down toilets and drains. In
the ecosystem, they are known as endocrine disrupters, settling into cell
receptors intended for hormones and garbling the body's chemical
communications.

To bolster his evidence, in 2005 Norris and colleague Alan Vajda, a CU
research associate, set up the Fish Exposure Mobile in a trailer borrowed
from the Colorado Division of Wildlife. U.S. Geological Survey scientists
Larry Barber and James Gray also are working with Norris' team, and the city
of Boulder's cooperation also has been vital, the scientists say.

Where Norris and Vajda are what Barber called "world-class endocrinologists,"
Barber and Gray are chemists who have advanced detection techniques to the
point they can spot human estrogen in concentrations as low as 0.2 parts per
trillion.

They needed such exactitude because human estrogen, or 17 beta estradiol,
affects fish at concentrations as low as one part per trillion - the
equivalent of a pinch of salt in an Olympic pool, Norris said.

Barber said volumes of human estrogen in the pure treatment-plant effluent
range from one part per trillion to about 10 parts per trillion.

The Fish Exposure Mobile, parked next to the creek on sewage treatment plant
property, pulls water directly from the plant's outflow pipe and can dilute
it using precise volumes of upstream Boulder Creek water.

Fathead minnows swim in two identical tanks inside, each 200 gallons. One
fills with upstream creek water; the other with varying degrees of wastewater
plant effluent. Such control lets researchers see how fish react to varying
effluent concentrations.

They aimed to create a controlled experiment and confirm if estrogen and
other compounds from the treatment plant were responsible for the fish sex
change.

"The males were feminized in seven days," Norris said. "You don't need a
Ph.D. to sex them."

The males have bumps on the forehead and often attack each other. The fish
exposed to the effluent water lost their bumps and acted like girls. It
confirmed effluent to be the culprit.

Diluting the treatment plant's effluent 50 percent feminized breeding male
fish in a week to 15 days, Norris said. Some of the effects remained evident
even when the wastewater plant effluent was diluted 75 percent.

"We were excited to get these results, but at the same time we're a little
bit appalled at what we've seen," Norris said.

Sheila Murphy, a hydrologist with the U.S. Geological Survey in Boulder, said
the Fish Exposure Mobile work has been important to counter skeptics who
attribute transsexual fish in the Potomac River and other waterways to
temperature changes or other environmental influences.

"What it's showing is that it's indeed from the wastewater plant," Murphy
said.


Laurie J. Tenace
Environmental Specialist
Florida Department of Environmental Protection
2600 Blair Stone Road, MS 4555
Tallahassee, Florida 32399-2400
PH: (850) 245-8759
FAX: (850) 245-8811
Laurie.Tenace at dep.state.fl.us  
 
view our mercury web pages at: 
http://www.dep.state.fl.us/waste/categories/mercury/default.htm 

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