Something in the Water Is Feminizing Male Fish. The prime suspect? Our toilets. wastewater treatment plants flush endocrine-disruptive compounds (EDCs), including pharmaceuticals, pesticides and hormones, into rivers. Even minuscule amounts of EDCs can trigger powerful hormonal shifts that deform male fishes? reproductive organs. During a seven-year study, for instance, scientists added parts-per-trillion amounts?the levels emitted by treatment plants?of the synthetic estrogen used in birth-control pills to a closed lake. The resulting sex changes collapsed the entire fish population.Given that intersex fish were found both upstream and downstream of wastewater treatment plants, some scientists also think agricultural runoff could be the cause. 100 percent of smallmouth bass to be intersex along parts of the Shenandoah River, where rain washes waste laden with hormones excreted from millions of chickens and cattle into the water. compounds can interfere with the human endocrine system, but there are no regul
