Rivers and groundwater are being contaminated with minute amounts of everything from antibiotics and birth control pills to chemicals used in cosmetics, scientists said this week at the American Chemical Society’s annual meeting in San Francisco. The issue is only beginning to be studied, and scientists have no idea what the combined effects on humans are of pharmaceuticals and personal care products in the environment. Scientists from the U.S. Geological Survey have found low levels of anti-depressants and many other compounds in water supplies, as well as notable amounts of caffeine, which they call “the Starbucks effect.” European researchers have found high concentrations of chemicals from sunscreens, shampoos, and detergents accumulating in the flesh of fish, and some believe that estrogen replacement drugs have caused fish deformities.