Does it matter that pharmaceuticals are turning up in water supplies?
By JANET RALOFF
|Some male fish in Lake Mead (dark blue waters) produce an egg-yolk protein normally made only by reproducing females. Scientist have tracked human estrogens from a sewage treatment plant, down the Las Vegas Wash (the light blue stream on the center right), and into the lake.|
|Unlike facilities today, these old-style settlement ponds on a sewage treatment farm south of Berlin rely on light and natural bacteria to cleanse the water. However, drugs and other undegraded contaminants can seep from them into groundwater.|
|While many of the drugs being detected in water are prescribed only for people, others may also be used in veterinary medicine or animal husbandry. For instance, aquaculture uses high volumes of antibiotics. These medications can stem infection in fish such as the coho and Chinook salmon being raised in pens here in the Puget Sound. When delivered directly into water, as they are in the long string of open pens, antibiotics may also affect other wildlife. In contrast, drugs added to closed containment systems like the ring-shaped one are filtered out before the water is returned to the open environment.|