Drinking water gets a drug test
Federal scientists surveying fish in the Potomac River continue to find smallmouth bass with a freakish quirk: The males are making eggs and sperm.
Researchers suspect that these "intersex" bass are victims of a newly recognized form of pollution: trace amounts of pharmaceuticals and other chemicals flushed down toilets or flowing from farms' animal waste.
Compounds including antibiotics and caffeine drain through sewage systems largely untouched, collect in rivers and streams, and eventually return in tiny amounts to drinking water.
Until recently, those pollutants had been virtually undetectable because the concentrations are so low. But instruments now can identify substances in parts per trillion - each part equivalent to a grain of sand in an Olympic-size swimming pool - and scientists are finding traces of man-made chemicals in streams in Chester County and drinking-water supplies in Philadelphia and other cities.
The effect on human health is unknown, but the discovery has prompted a flurry of research to measure and remove the trace chemicals.
The Philadelphia Water Department is participating in a $1 million national study to measure pharmaceuticals and other chemicals in drinking water.
Governments in places as diverse as Maine and Ireland are moving to keep the compounds out of the water supply.
Even a town as small as Buckingham Township has gotten in the act. The farm-rich Bucks County community plans to require residents to dispose of drugs in special boxes rather than flushing them.
And Villanova University scientist Rominder Suri has received a federal grant to use sound waves to break apart trace compounds and render them inert.
Some experts fear that traces of antibiotics could worsen bacterial resistance and cause those lifesaving drugs to lose potency. Or that the wide range of compounds could have some unknown cumulative effect on people. No one really knows.
Christopher S. Crockett, manager of watershed protection at the Philadelphia Water Department, said the concerns must be kept in perspective. "In 1948, the Delaware smelled so bad that you could smell it at Broad Street" - 14 blocks away, said Crockett, whose agency found several parts per trillion of 13 common drugs in the Schuylkill in 2004.
"To be able to look for these chemicals at these levels is a luxury," Crockett said, adding "we are ready to take action if necessary."
There is no mystery how the compounds get into water. They pass through the sewage system in waste or pill form.
They flow from pharmaceutical plants that make drugs and flush away the residue. Or they seep from animal farms that use antibiotics and rarely treat their waste.
Fish seem to have borne the brunt of the chemicals' effects so far.
The presence of dual-sex bass in the Potomac is likely connected to the widespread use of "endocrine disrupters," substances that mimic hormones and cause male fish to develop female attributes, researchers said.
Those chemicals include the synthetic hormones in birth-control and hormone-replacement therapy and substances in such common products as shampoos and sunscreens.
While no one has found intersex fish in Southeastern Pennsylvania, Vicki S. Blazer, a fish pathologist for the U.S. Geological Survey, said she would not be surprised if someone did.
Blazer first found the deformed fish in the Potomac and Shenandoah Rivers. Many of the chemicals that cause intersex fish also weaken their immune systems, causing them to die or develop lesions, she said.
Fish kills in the last year on Pennsylvania's Juniata and Susquehanna Rivers resembled those that led to the discovery of intersex fish in Maryland and West Virginia, Blazer said.
The estrogens that worry Blazer have been found in the Philadelphia area. A survey directed by Villanova's Suri found natural or synthetic estrogens in all 21 streams tested in southern and central Chester County in the fall of 2004.
Levels of a potent synthetic estrogen in birth-control treatments - ethinyl estradiol - were found in 10 streams at levels up to 30 times the amount that, in the lab, had been shown to affect the sexual organs of fish, he said.
Suri called the contaminants an "emerging environmental issue" that should change the way sewage is treated. Hospitals and nursing homes may eventually have to install equipment to remove the drugs from waste, he said.
The Schuylkill basin, which supplies water to 1.5 million people, could pose a special challenge. Water intake pipes are downstream from the river's confluence with Wissahickon Creek, which carries effluent from five sewage plants and a Merck pharmaceutical factory.
City water officials found tiny amounts of 13 drugs in tests of Schuylkill water during the summer of 2004. Among those were over-the-counter painkillers, antibiotics, antidepressants, and the contrasting agents that patients drink to make X-rays work better.
The department also tested drinking water and found parts per trillion of six chemicals, including estrogen, antidepressants, and the insect repellent DEET.
"It is a limited snapshot, and that is why we are doing the follow-up work," said Crockett, who thinks the water is safe.
Nick DiNardo, coordinator of the Environmental Protection Agency's Innovation Action Council for the Mid-Atlantic region, said the EPA was far from setting acceptable levels of pharmaceuticals in treated waste. Such limits would be established "way after the research is done," he said.
Last month, DiNardo's group gave a $101,000 grant to Villanova's Center for the Environment, which Suri directs, to develop ultrasound technology that can remove the waste.
Suri has also gotten support from a Villanova neighbor, the pharmaceutical firm Wyeth, to explore the technology. Wyeth does not make pills in Pennsylvania, a spokesman said.
The ultrasound treatment works by blasting wastewater with sound waves, creating heat and chemical reactions that destroy pharmaceuticals.
Suri also is looking into low-tech methods, such as collection boxes for drugs at universities and health facilities.
But this method could be complicated because of federal guidelines for handling controlled substances. Collection sites require the presence of a law enforcement officer.
Last year, Maine arranged its first drug collection in a pharmacy. Fifty-two people turned in 55,000 pills as police looked on.
But Maine psychiatrist Stevan Gressitt, a key supporter of the state's drug-collection law, said a more thorough solution was needed. In a few months, Maine will begin allowing residents to mail unused drugs to the state.
Gressitt called this "an industrial-sized solution" that could help keep drugs out of drinking water nationally.
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