Chicago officials have never tested the city and suburban water supply for pharmaceuticals and other unregulated chemicals, even as concern grows about the possible health effects of trace amounts of drugs in drinking water.
So the Tribune and RedEye did the testing the city won't do.
Trace concentrations—measured in parts per trillion—were found in water collected at City Hall, an elementary school on Chicago's South Side and a public library in Waukegan, which has its own treatment plant.
The Tribune's findings echo what authorities have detected in tap water supplies elsewhere in the country: dozens of prescription and over-the-counter drugs as well as chemicals from personal-care products, food packaging, clothing and household goods.
The tests do not show that drinking water is unsafe. But they do raise important questions for regulators and city officials aware of growing concerns about potential health effects from long-term exposure to drugs in our drinking water, even at very low levels.
"There are many unknowns," said Dana Kolpin, a researcher at the U.S. Geological Survey who conducted some of the first tests that found pharmaceuticals in municipal water supplies. "On one hand, levels of specific substances are very low and appear to be nothing to worry about. But the question is whether mixtures of many substances could build to a point where there could be some harmful effects."
Drugs end up in drinking water after people take medications and some of the residue passes through their bodies. Conventional sewage and drinking water treatment filter out some of the substances, or at least reduce the concentrations, but multiple studies have found small amounts get through.Responding to the findings in other cities, Gov. Rod Blagojevich announced last month that the state would test tap water in Chicago and a handful of Downstate communities for the first time. Chicago doesn't plan to conduct its own tests unless required to do so by federal regulators, according to a March 7 letter sent by the Department of Water Management in response to a Tribune inquiry.
Using sampling techniques and containers provided by the University of Iowa Hygienic Laboratory, Tribune reporters took samples on March 17 from drinking fountains at City Hall, Sherman Elementary on the South Side, and the Waukegan Public Library. Water from a tap at Tribune Tower also was filtered through a household filter before collection.
The water samples were shipped to the Iowa lab and analyzed for nearly 40 different compounds, including regulated pesticides and heavy metals and unregulated prescription and non-prescription drugs.
The tests did not reveal the presence of most of the contaminants But water from a drinking fountain on the 7th floor of City Hall, just outside the Department of Streets and Sanitation, contained small amounts of carbamazepine, a prescription drug used to control epileptic seizures and treat bipolar disorder. Also found was acetaminophen, an over-the-counter painkiller.
Water from all three of the drinking fountains also contained small amounts of cotinine, a byproduct of nicotine. In addition, caffeine was found in the water from Sherman Elementary.
Because coffee and tobacco are widely consumed, researchers consider cotinine and caffeine to be indicators of other pharmaceuticals that could be found in human waste, similar to the way the presence of E. coli is used as a gauge of bacterial contamination in water.
The newspapers also had the lab test the region's top three brands of bottled water, Ice Mountain, Dasani and Aquafina, and no pharmaceuticals were found. A sample of Lake Michigan tap water passed through a Brita filter also tested negative.
City officials stress the region's tap water supply is safe. And federal regulators contend they don't have enough evidence to limit pharmaceuticals or many other unregulated chemicals in the environment or in drinking water. Medical experts, meanwhile, say there is no reason to stop drinking tap water.
The Tribune informed the city about the test results April 3. City officials have since declined to answer questions in person or over the telephone. In a three-paragraph e-mail response, they questioned the newspaper's collection methods and touted the city's efforts to safely dispose of unused pharmaceuticals.
"The quantities you say were found are extremely minute, and pose no known hazard," the city's statement read. "Nevertheless, we are aware of this new area of scientific interest, and we are working with government regulators and the scientific community to help develop tests and protocols to ensure the safety of our water source and the treated water we deliver to our customers."
Most of the Lake Michigan drinking water consumed in Illinois is treated by Chicago, then piped to outlying suburbs, which do nothing more to treat it.
Waukegan is among a handful of North Shore communities with its own treatment plant. Jeff Musinski, the plant's director, suggested the cotinine, Teflon and Scotchgard chemicals found in a sample drawn from the Waukegan library could have been inadvertently left by custodians while cleaning the drinking fountain—a theory rejected by the Iowa lab that performed the tests.
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