Synthetic chemicals pose growing threat to global water supply

Synthetic chemicals that damage the human reproductive system are creeping into the world's water supply. Scientists say the chemicals, once waterborne, can quickly spread throughout the globe. They're in pesticides and solvents - and even in our medications. An insidious threat to humans and animals, so-called xenobiotics are mostly synthetic chemicals that can interfere with the endocrine system and even act as poisons. When the chemicals become waterborne they can wreak havoc, especially on the human reproductive system, according to Swedish hydrologist Malin Falkenmark. "These substances are a serious problem for us and for future generations, because they impact human fertility," Falkenmark said. "In order to tackle this threat, we have to have to track down the source of the pollution. Once a substance is released into water it spreads throughout the world, because there is water everywhere." Perhaps the best-known example of xenobiotics comes from oral contraceptives. When women take birth-control pills, their bodies pass the synthetic estrogen and progesterone out as waste into the water supply.