Annual water quality reports mailed to Chicagoans this month didn’t say a word about sex hormones, painkillers or anti-cholesterol drugs, even though city officials found traces of pharmaceuticals and other unregulated substances in treated Lake Michigan water during the past year.
Like other cities, Chicago must notify the public if its drinking water contains certain regulated contaminants, including lead, pesticides and harmful bacteria.
But pharmaceutical chemicals, which have been detected in drinking water across the country, are not on that list. So Mayor Richard Daley is technically correct in stating that the “pure, fresh drinking water” pumped to 7 million people in Chicago and the suburbs “meets or exceeds all regulatory standards.”
Drinking water standards haven’t been updated for years, in part because little is known about how pharmaceutical concoctions might affect public health. But researchers and regulators are concerned about the potential effects of long-term exposure to these substances, which are designed to have an impact at low doses.
“We’re just scratching the surface with what’s been detected to date,” said Dana Kolpin, a researcher at the U.S. Geological Survey. “And we don’t have a clue about what these mixtures can do.”
Chicago officials didn’t start conducting their own tests until last year, after a Tribune investigation found small amounts of pharmaceuticals and other unregulated chemicals in samples of the city’s tap water.
The city collected samples of treated Lake Michigan water four times in 2008. According to results posted on the city’s Web site, the tests found small amounts of the sex hormones testosterone and progesterone; gemfibrozil, a prescription cholesterol-fighting drug; ibuprofen, an over-the-counter painkiller, and DEET, the active ingredient in bug spray.
The tests also found caffeine, nicotine and cotinine, a nicotine byproduct, all of which researchers consider to be indicators of pharmaceuticals from human waste.
Drugs end up in drinking water after people take medications and some of the residue passes through their bodies down the toilet. Conventional sewage and water treatment filters out some of the substances, or at least reduces the concentrations, but multiple studies have found that small amounts still get through.
Although treated sewage from the Chicago area drains away from Lake Michigan, more than 300 other cities put treated waste and untreated sewage overflows into the lake and its tributaries, according to the U.S. Environmental Protection Agency.
Chicago’s tests found tiny amounts of the antidepressant Prozac and sulfamethoxazole, an antibiotic, in untreated water collected from Lake Michigan intake cribs. But those prescription drugs weren’t found in treated water. Nor were most of the 71 other unregulated compounds the city screened for.
The Daley administration first promised to test for pharmaceuticals monthly, then changed course after the first tests turned up inconsistent results. Now officials plan to collect samples three times a year and send the water off to be tested by three different labs.
“We haven’t seen any patterns yet, so it’s tough to reach any conclusions,” said John Spatz, the city’s water commissioner. “But since it’s an emerging issue, we’re going to keep following it.”
As promised, the test results are available online. Yet it requires considerable sleuthing to find them on the Department of Water Management’s home page, and the drugs found in the water are not easily discernible amid six pages of numbers.
In the Tribune’s tests, conducted in March 2008, water drawn from a drinking fountain at City Hall contained trace amounts of cotinine; carbamazepine, an anti-seizure drug; and acetaminophen, an over-the-counter painkiller. The newspaper’s tests also found two unregulated industrial chemicals used to make Teflon and Scotchgard, neither of which the city tested for.
Even though such substances are turning up virtually every time researchers look for them, the EPA says it still doesn’t have enough evidence to limit pharmaceuticals and many other unregulated chemicals in drinking water — in part because cities haven’t been required to test routinely for the compounds.
The Obama administration’s top water regulator, Peter Silva, promised at his confirmation hearings to step up the government’s research efforts. Without direction from federal officials, cities across the nation have slowly begun to test their water for pharmaceuticals, prompted by studies in Europe and later by the U.S. Geological Survey.
Milwaukee, which also draws its drinking water from Lake Michigan, added dozens of pharmaceuticals three years ago to its annual testing for unregulated contaminants and posts easy-to-understand results online. Nothing turned up last year, according to the city’s site.
Water officials say not enough is known to justify spending millions of taxpayer dollars to upgrade treatment plants so they could strip the chemicals from the water. The most effective method, reverse osmosis, is expensive and creates a large amount of waste.