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.

The newspapers hired an independent lab, which found tiny amounts of an anti-seizure drug, a common painkiller, caffeine and two chemicals used to make Teflon and Scotchgard in samples taken from a water supply that serves 7 million people.

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.

He also acknowledged Waukegan has not tested drinking water for the same compounds.

"This isn't a problem," Musinski said. "But it is a problem if your reporting erodes public confidence in our water supply."

The Tribune's testing cannot tell the full story of what chemicals might exist in a glass of water drawn from your tap. The number of samples was small, the lab tested for only a certain number of substances and the findings were different for each sample.

Experts, though, say the discovery of any unregulated chemicals signals they are commonly present in Lake Michigan, the region's chief source of drinking water. The substances likely have been there for as long as they've been used; they just weren't detected until analytical methods improved.

Many of these drugs and chemicals end up in the environment after flowing through sewage treatment plants. People absorb some of the medicine in every pill they take. The rest passes through their bodies, flushes down the toilet and eventually washes into water supplies.

Even though treated sewage from the Chicago area drains away from Lake Michigan, there are more than 300 other cities that dump treated waste into the lake and its tributaries, according to the U.S. Environmental Protection Agency.

There has been little study of pharmaceuticals in Lake Michigan. But recent tests of treated sewage that Milwaukee pumps into the lake found several drugs, including carbamazepine, acetaminophen and tetracycline, a commonly prescribed antibiotic.

"You found some of the same things we are finding out there," said Rebecca Klaper, a researcher at the University of Wisconsin-Milwaukee's Great Lakes Water Institute.

Last month, The Associated Press reported test results from two dozen cities where drugs were found in drinking water. But the EPA does not require utilities to test for pharmaceuticals, and most of the cities that have conducted their own studies have been reluctant to share the results.

Milwaukee is a notable exception. Since 1993, when Cryptosporidium parasites in Milwaukee's water killed more than 100 people and sickened 400,000 others, the city has aggressively tested for unregulated contaminants. Last year, it added dozens of pharmaceuticals to the list.

The city's water department now tests for 450 unregulated contaminants twice a year and posts the results on its Web site. Several compounds were found last year in Lake Michigan, including caffeine, two antibiotics and gemfibrozil, a cholesterol-fighting drug. Small amounts of cotinine and the antibiotic lincomycin were found in treated drinking water, but not carbamazepine or acetaminophen.

"We believe strongly in full disclosure," said Carrie Lewis, superintendent of the Milwaukee Water Works. "We've got an educated audience out there that wants all the information we can give them."

John Vargo, the environmental program manager at the University of Iowa lab that conducted the Tribune's tests, said he has found traces of carbamazepine, acetaminophen and other pharmaceuticals in the drinking water of other Midwestern cities. He declined to reveal the specific locations, citing confidentiality agreements written into the lab's contracts.

Carbamazepine, cotinine and caffeine also have been frequently found in drinking water tested by the U.S. Geological Survey and the American Water Works Association, a utility trade group. Acetaminophen has been detected, too, though less frequently.

Other researchers are trying to figure out which drugs pose the greatest health risks. Some over-the-counter medications might be found in higher concentrations in drinking water, for instance, but small amounts of chemotherapy drugs and birth control pills could prove to be more toxic. Moreover, there are many drugs, pesticides, detergents and other chemicals that mimic human hormones. These substances, known collectively as endocrine disrupters, are seen as potential contributors to various types of cancer, birth defects and developmental problems.

"What we are seeing are the inconvenient consequences of a convenient lifestyle," said Conrad Volz, a researcher at the University of Pittsburgh who studies environmental hazards. "Given what we already know about many of these compounds, there is reason for concern."

Two industrial chemicals found in tap water tested for the Tribune, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), are unregulated substances that for decades were used to make Teflon and Scotchgard stick- and stain-resistant coatings.

Under pressure from the EPA, 3M stopped making the compounds in 2000, prompted by research that found the chemicals in human blood and in foods such as apples, bread, green beans and ground beef. DuPont still uses PFOA to make Teflon and related coatings, but agreed to stop manufacturing the chemical by 2015 after the EPA declared it likely causes cancer.

One recent study also linked exposure to the chemicals to low birth weights in newborns. The findings concern regulators because the compounds don't break down in the environment and stay in human blood for at least four years.

Drinking water is one potential source of exposure. Researchers studying the chemicals in the Great Lakes think that when carpets and clothing treated with PFOA and PFOS are cleaned, some of the residue washes into sewage treatment plants that are not equipped to remove them. Runoff from landfills and storms could be another source.

But while these chemicals and pharmaceuticals keep showing up nearly everywhere researchers look, federal officials say they still don't know enough to regulate them.

"This is a growing concern, and we are taking it very seriously," said Benjamin Grumbles, the EPA's assistant administrator for water. "I think we're asking all of the right questions. We just don't have the answers yet."

Klaper, the University of Wisconsin-Milwaukee researcher, said Great Lakes scientists have drafted several proposals to conduct more study of pharmaceuticals in Lake Michigan. The EPA declined to fund the work.

Michael Hawthorne is a Tribune reporter. Alexia Elejalde-Ruiz is a reporter for the Tribune's RedEye edition.

mhawthorne@tribune.com

aelejalderuiz@tribune.com