Think Before You Drink

Millions of Americans drink tap water that is contaminated with chlorination byproducts (CBPs) at levels that are dangerous for pregnant women, according to a report by the Environmental Working Group and U.S. Public Interest Research Group. The groups found that since 1995 more than 1,200 communities served CBP-contaminated water to more than 16 million people for periods of up to 12 months.

Water utilities chlorinate water to eliminate disease-causing microorganisms. CBPs are formed when chlorine is added to water that contains organic matter such as runoff from lawns and farms. And CBPs pose serious health risks to expectant mothers, among them miscarriage and birth defects, according to at least 10 major peer-reviewed epidemiological studies. In addition, the U.S. Environmental Protection Agency estimates that CBPs cause 9,300 cases of bladder cancer each year.

The solution, according to the report, is to improve the quality of the nation's drinking water by cleaning up pollution in lakes and streams and reducing agricultural runoff.

In the meantime, what can consumers do? Pregnant women, or anyone worried about ingesting CBPs, can install carbon filters on faucets and shower heads or drink nonchlorinated bottled water. Also, in summer when CBP levels are highest, it's a good idea to take shorter showers to minimize exposure. (The EPA has a safe-water hotline providing the latest information on water quality: 800.426.4791.)

—Kristine Merrill