U.S. water supply contaminated by pharmaceuticals

nine different drugs in water samples. Japanese health officials in December called for human health impact studies after detecting prescription drugs in drinking water at seven different sites. In the United States, the problem is not confined to surface waters. Pharmaceuticals also permeate aquifers deep underground, source of 40 percent of the nation’s water supply. Federal scientists who drew water in twenty-four states from aquifers near contaminant sources such as landfills and animal feed lots found minuscule levels of hormones, antibiotics and other drugs.

Perhaps it is because Americans have been taking drugs — and flushing them unmetabolized or unused — in growing amounts. Over the past five years, the number of U.S. prescriptions rose 12 percent to a record 3.7 billion, while nonprescription drug purchases held steady around 3.3 billion, according to IMS Health and The Nielsen Co. “People think that if they take a medication, their body absorbs it and it disappears, but of course that’s not the case,” said EPA scientist Christian Daughton, one of the first to draw attention to the issue of pharmaceuticals in water in the United States. Some drugs, including widely used cholesterol fighters, tranquilizers, and anti-epileptic medications, resist modern drinking water and wastewater treatment processes. Plus, the EPA says there are no sewage treatment systems specifically engineered to remove pharmaceuticals.

One technology, reverse osmosis, removes virtually all pharmaceutical contaminants but is very expensive for large-scale use and leaves several gallons of polluted water for every one that is made drinkable. Another issue: There is evidence that adding chlorine, a common process in conventional drinking water treatment plants, makes some pharmaceuticals more toxic.

Human waste is not the only source of contamination. Cattle, for example, are given ear implants which provide a slow release of trenbolone, an anabolic steroid used by some bodybuilders, which causes cattle to bulk up. Not all the trenbolone circulating in a steer is metabolized. A German study showed 10 percent of the steroid passed right through the animals. Water sampled downstream of a Nebraska feedlot had steroid levels four times as high as the water taken upstream. Male fathead minnows living in that downstream area had low testosterone levels and small heads. Other veterinary drugs also play a role. Pets are now treated for arthritis, cancer, heart disease, diabetes, allergies, dementia, and even obesity — sometimes with the same drugs as humans. The inflation-adjusted value of veterinary drugs rose by 8