That's the best way to keep them away from people who shouldn't have them, including children, poison prevention groups and pharmaceutical associations say.

But growing evidence suggests that flushing pharmaceuticals poses environmental risks.

The Orange Water and Sewer Authority is recommending packaging unused drugs and putting them in the trash.

But that still might give children or others access to controlled substances, said Terri Buckner, an OWASA board member.

"It's quite a dilemma," she said.

The effect on humans of chemicals in the water supply is unknown. But Christian Daughton, chief of the U.S. Environmental Protection Agency's environmental chemistry branch in Nevada, has found that drugs such as Prozac can affect aquatic life.

A concentration as low as one part per billion of the active ingredient in Prozac, an antidepressant, can affect the spawning patterns of fish, or make them less or more afraid of predators, he said.

And a wide variety of drugs has been flushed for decades, Daughton said; "no organism is ever exposed to just one chemical at a time."

The EPA held a conference last year on pharmaceuticals in the environment. Little standardized testing has been done, the National Association of Clean Water Agencies reported, but "measurable amounts of medications for pain, depression, and colds; birth control pills; caffeine; hair product ingredients; cleaning supplies; and pesticides are all being detected in samples collected from U.S. waterways."

This "raises obvious questions about potential risks to human health and the environment," it said.

Daughton said it's nearly impossible to quantify how many drugs are put into sewer systems, though tests have detected only trace amounts in the water supply. Local officials are considering ways to reduce chemicals in the water.

When drugs are flushed or sent down a sink drain, they go to a wastewater treatment facility.

In Orange County's case, pollutants are removed, and the remaining liquid effluent is treated and sent into Morgan Creek.

That feeds Jordan Lake, a water source for parts of western Wake and eastern Chatham counties.

Any lake water drawn for drinking is treated again, so Daughton says the risk to humans from pharmaceutical chemicals in drinking water appears low; the main concern is the lake, he said.

Daughton said researchers have begun looking seriously at pharmaceuticals in the water supply in the last five years, in part because new testing methods make it possible to detect elements down to the one-part-per-trillion level.

"If you get down far enough, you can find just about anything," Daughton said. "Then you're left with the question, 'Well, what does that mean?' "

Sandra Bradshaw, OWASA's laboratory manager, said she isn't sure what to make of the new information. "There's still a lot of ambiguous data out there," she said.

But Buckner, the OWASA board member, wants an education program to get people to stop flushing. OWASA also might look into treatment systems that could remove chemicals more effectively.

"The science is indicating those drugs do have long-lasting effects and are showing back up in our water supply," she said. "Our current testing and treatment systems are not intended to eliminate them."

Alternatives are few

Some local health-care providers already are taking the steps OWASA now recommends.

UNC Hospitals usually has drugs incinerated.

The Carolina Meadows retirement community in Chapel Hill also has unused drugs taken to the nursing facility for later incinerating, said Joe Zannini, director of plant operations.

But John Woodard, owner of Sutton's Drug Store on Franklin Street, said he does flush what little expired medicine he has.

"It's the simplest and safest way to get rid of 'em," Woodard said. "I imagine there's a lot more cooties and things going into the sewer than anything we could throw down there."

Daughton said the alternatives to flushing aren't great. Even if drugs reach the landfill, they could seep through the lining, he said.

Officials in Maine, however, think they have a better idea.

A test program there will urge people to mail unused drugs to a post office box monitored by state drug enforcement agents, who will destroy the medicines.

Dr. Stevan Gressitt, who pushed for the program, said it's a good, if imperfect, fix.

"It's a boutique solution," he said. "Cute, small, expensive, and somebody's paying for it. Are boutique solutions what we need in this country for what is truly an industrial-sized problem?"

A national policy won't be in place until EPA officials learn more about the risks, Daughton said. That could take a while.

"Science usually doesn't progress in leaps and bounds," he said.

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