Drugs in Our Drinking Water?
Experts put potential risks in perspective after a report that drugs are in the water supply.
WebMD Health News
Reviewed By Louise Chang, MD
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.
Are certain people — say pregnant women, children, the elderly — more sensitive to the potential effects of drugs in the drinking water supply?
Again, it's not known, Janssen says. "We know that kids, including babies and toddlers, as well as fetuses, are more susceptible to environmental exposures because their bodies are still developing and their exposure on a pound-per-pound basis is higher. And they lack the detoxification system adults have. So it is not unreasonable to expect they would be at higher risk."
Can boiling tap water get rid of the medicines, or would drinking bottled water solve the problem?
Boiling will not solve the problem, Janssen says. And forget bottled water as a way to escape the low levels of drugs found in some public water supplies. "Twenty five percent of bottled water comes from the tap," she says, citing an NRDC report.
Labels on bottled water, regulated by the FDA, help consumers know what they are getting, says Stephen Kay, a spokesman for the International Bottled Water Association. If bottled water companies use water from municipal sources and do not treat it further to purify it, the FDA views the source as legitimate but requires the label to state that it is from a municipal or community water system. Bottled water companies that use municipal source water, but then treat and purify it by using reverse osmosis, distillation, or other processes can label it as such using terms such as "purified water" or "reverse osmosis" water.
Home filtering systems such as reverse osmosis may reduce the medication levels, says Timothy Bartrand, PhD, a postdoctoral fellow at Drexel University, Philadelphia, who participated in a National Science Foundation workshop to develop a drinking water research agenda.
"An activated charcoal system will remove some pharmaceutical drugs but not all," Janssen says. "A reverse osmosis system can also remove some."
What else can consumers do to find answers or improve the situation?
Contact your local public utilities and ask them what pollutants they test for in drinking water, Janssen says, as one way to raise awareness of the problem. Contacting your senator or congressman is another.
When disposing of expired or unneeded medications, don't flush them, Rudzinski says. Instead, mix unused or unwanted drugs with coffee grounds or kitty litter, something that will be unpalatable to pets. Put the mixture in a sealed container so it's not accessible to children or pets and put the mixture in the trash.
SOURCES: Suzanne Rudzinski, deputy director for science and technology, Office of Water, U.S. Environmental Protection Agency, Washington, D.C. Sarah Janssen, MD, PhD, MPH, science fellow, Natural Resources Defense Council, San Francisco office. Timothy Bartrand, PhD., postdoctoral researcher in environmental engineering, Drexel University, Philadelphia. Associated Press Report, March 10, 2008. Stephen Kay, spokesman, International Bottled Water Association, Alexandria, Va.
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