Drugs in Our Drinking Water?

Tiny amounts of pharmaceuticals -- including antibiotics, hormones, mood stabilizers, and other drugs -- are in our drinking water supplies, according to a media report.

In an investigation by the Associated Press, drinking water supplies in 24 major metropolitan areas were found to include drugs.

According to the investigation, the drugs get into the drinking water supply through several routes: some people flush unneeded medication down toilets; other medicine gets into the water supply after people take medication, absorb some, and pass the rest out in urine or feces. Some pharmaceuticals remain even after wastewater treatments and cleansing by water treatment plants, the investigation showed.

Although levels are low -- reportedly measured in parts per billion or trillion -- and utility companies contend the water is safe, experts from private organizations and the government say they can't say for sure whether the levels of drugs in drinking water are low enough to discount harmful health effects.

WebMD asked experts to give their take on the potential risks of drugs in the water supply.

Is this a new phenomenon, the finding of pharmaceuticals in public water supplies?

No. Low levels of pharmaceuticals in the water supply have been a concern for a decade or longer, says Sarah Janssen, MD, PHD, MPH, a science fellow at the Natural Resources Defense Council, an environmental action group.

"Ever since the late 1990s, the science community has recognized that pharmaceuticals, especially oral contraceptives, are found in sewage water and are potentially contaminating drinking water," Janssen tells WebMD.

Concern among scientists increased when fish in the Potomac River and elsewhere were found to have both male and female characteristics when exposed to estrogen-like substances, she says. For instance, some fish had both testes and an ovary, she says.

Scientists starting looking at the effects of oral contraceptives first, she says. "Now analyses have expanded to look at other drugs," Janssen says.

Technology has made this research easier, says Suzanne Rudzinski, deputy director for science and technology in the Office of Water at the U.S. Environmental Protection Agency. "Analytical methods have gotten better and we are able to detect lower levels than ever before."

Is there a health effect of drugs in drinking water?

All sides of the debate agree this is not known for sure. "At this point we don't have evidence of a health effect," Rudzinski says, "although it's an area of concern and one we will continue to look at."

Janssen agrees: "We don't know. It's true that the levels [of the medications found in drinking water] are very low. But especially when it comes to pharmaceuticals that are synthetic hormones, there is concern, because hormones work at very low concentrations in the human body."

"We don't want people to be alarmed and think they can't drink their tap water or that they shouldn't be drinking water," Janssen says. "We think this report in particular is a call for our federal agencies -- EPA in particular -- to do further studies to see what the health effects are."

EPA's ongoing research is focusing on the effect of pharmaceuticals in the water supply on aquatic life and human health, Rudzinski says. But she could not supply details of how much money is being allocated to that research effort or when to expect answers.