Water is Becoming a Dangerous Drug

Birth control pills, estrogen replacement drugs, ibuprofen, bug spray, sunscreen, mouthwash and antibacterial soap: all of these products could turn up in your next glass of tap water, according to the United States Geological Survey (USGS). Last summer, USGS scientists sampled 139 rivers and streams, finding hundreds of prescription and over-the-counter drugs and personal care products lingering in the nation's water supply.

In many cases, these tiny drug particles were found in river water that is recycled -- flowing from one city's sewer plant into another city's drinking water system. Many cities can't afford the charcoal filters required to screen out the final traces of these byproducts, so they end up in the drinking water, experts say. Rural homeowners who use well water are at an even greater risk. USGS researchers also turned up antibiotics in nearly half the streams that were sampled, raising other concerns about the nation's growing antibiotic resistance problem. "This study raised a bunch of red flags," says Dana Kolpin, lead author of the USGS study. "At these low concentrations, I think there are going to be long-term effects that may take several generations to show up."

A Threat to Reproductive Health

The dangers of endocrine-disrupting water pollutants such as dioxin and polychlorinated biphenyls (PCBs) are well known -- they have been linked to a variety of reproductive health problems, from endometriosis to low sperm counts. Synthetic hormones in the water may have similar health effects -- on both people and wildlife -- at very low levels of exposure. "All of these compounds are going into a chemical soup," says Theo Colborn, senior scientist at the World Wildlife Fund (WWF) and author of "Our Stolen Future."

Colborn says she is worried about pharmaceutical estrogens mixing with chemicals already present in streams. "You can liken it to side effects you get with a prescription drug -- you don't know how it's going to interact with the over-the-counter drugs you're taking," Colborn says. "It's the unexpected, interactive effects we never predicted that are a real concern."

For example, Colborn says, bisphenol A, a component of plastic that is also used as a fire retardant, causes female mice to reach puberty earlier than normal. Bisphenol A forms a weak bond with the body's estrogen receptors. It can scramble a cell's natural communication system and cause it to replicate too quickly. That, in turn, raises concerns about breast cancer in humans. What happens if this compound, which is active at low levels of exposure, combines with estrogen from a birth control pill in the water? At this point, it's still unclear. Colborn says, "It could have long-term health effects."

These estrogens also could have an additive effect with chemicals such as PCBs, which are found in animal tissue. A recent study by researchers at Michigan State University found mink that were fed a diet of PCB-laden fish from the polluted Housatonic River in Connecticut had offspring with lower birth weights and higher infant mortality rates. Housatonic Riverkeeper Tim Gray, a member of the New York-based Waterkeeper's Alliance, wonders if PCBs interfere with the mink's reproduction, what will synthetic estrogen and other drugs do?

Until recently, people thought the estrogens in birth control pills were rendered inactive by the body because the kidneys tack on an extra sugar molecule before they are excreted, says William Owens, a toxicologist who researched estrogen patches for Procter & Gamble. But now, scientists have learned bacteria in sewage treatment plants chew off that sugar molecule.

A British researcher, John Sumpter, contributed to this discovery while studying fish living near a London wastewater treatment plant. He found male fish that were producing eggs. After he found the compound estradiol in the fish tissue, he concluded estrogens from birth control pills were part of the problem.