Doctors recommend drinking plenty of water to replenish lost fluids and wash away wastes. Just where do the excreted wastes go? At least a few, including hormones and heart drugs, end up in streams—and eventually someone else's drinking water, a new study finds.
Though the amounts detected in water from a Louisiana tap were small—just a few parts per trillion (ppt)—they can be biologically active, another study finds. At these concentrations, one of the hormones measured and another found in birth control pills alter the apparent gender of fish and, possibly, their fertility.
In a suite of yet more studies, collaborating state, federal, and university scientists report finding male carp and walleyes in Minnesota that were producing "sky-high" quantities of vitellogenin, an egg-yolk protein normally made only by females. Such feminization might explain the suspected inability of some adult male fish to make sperm. The researchers had caught the walleye