Oct. 25, 2001 | Suppose that three summers ago, in 1999, you lived in Atlanta and drank the water. Any idea what was in the water? Traces of caffeine, nicotine and Tylenol.

Atlanta is not unique -- the anecdote could be about any American city, and include nearly any palette of drugs you might imagine. The U.S. water supply is laced with residues of hundreds of medicinal and household chemicals, compounds that originate not at a Dow Chemical drainage pipe but from our own personal plumbing. The contaminants come from our bladders and bowels, our bathtub drains and kitchen sinks. As much as 90 percent of anything the doctor orders you to swallow passes out of your body and into your toilet. Wastes from farm animals are never treated -- and loaded with antibiotics and fertility hormones. As chemists make new concoctions, the water supply takes the hit.

The good news is that there is no acute peril, as there is from fecal bacteria or mercury. The medicine in our water is not present at levels that will produce immediate effects. We're talking about a few parts per billion or trillion of drugs like Paxil, Keflex or amoxicillin.

But the daily ingestion of these unprescribed nanococktails does pose potential long-term perils. The presence of trace amounts of antibiotics in the water supply may lead to resistant strains of bacteria. Vanishingly small doses of steroids and other chemicals may interfere with reproductive systems in all living creatures. And the cumulative effect of combinations of chemicals over long periods of time is unpredictable.

U.S. officials are uneasy discussing these dangers. So are water utilities. For now, nothing is being done to limit drugs in the water supply. Authorities say the threat isn't sufficiently clear, that they cannot justify taking action without more conclusive research data, and that the total concentrations of such chemicals is too small to worry about. But in Europe, especially in Germany, serious efforts to clean up the water supply have already begun.

Here in the United States, the full scope of the problem is about to loom larger. At a conference held in Minneapolis in early October, a gusher of new data was presented at the 2nd International Conference on Pharmaceuticals and Endocrine Disrupting Chemicals in Water.

There scientists learned what they had long suspected. Advil, caffeine and a nicotine byproduct called cotinine are routinely detected in U.S. water supplies. River and lake samples have come back with a variety of antibiotics, antidepressants, antacids, heart drugs, you name it. The EPA, for instance, reported that children in Ohio and North Carolina are drinking diluted levels of atrazine, a popular agricultural herbicide known to interfere with brain and reproductive tissues in lab experiments. In Kansas, Vermont and other states, experts are finding a potent industrial byproduct called nonylphenol. It originates in just about every shampoo, detergent or cologne in your home. In Louisiana, scientists found Tylenol and birth control hormones.

The list is long and troubling. An engineer at the University of California at Berkeley, David Sedlak, estimates there are 129 widely used drugs in municipal wastewater nationwide, 49 at levels above a key cutoff point for potential regulation.

It turns out that both natural processes and our low-tech sewage treatment processes don't completely clean up the drugs that we excrete. Reduced to their essence, most water-treatment plants remove the solid stuff and partly purify the liquid remainder before sending it into the environment. Only later, at some other facility downstream, will the water be rendered suitable for drinking. Everyone is downstream from someone.

Scientists say they are not alarmed. They regard the drugs-in-the-water phenomenon as a relatively low risk. The subtle health effects of parts-per-trillion concentrations are devilishly hard to confirm. So in New Mexico, it was no big deal when water engineers detected low concentrations of birth control hormones, the anti-seizure medicine Dilantin, the antidepressant Elavil and the painkiller Darvon. "We found a lot of Darvon," said Dennis McQuillan, a New Mexico water engineer. "I don't know what that says about the culture in our state." The audience in Minneapolis laughed.

Debra Moll, a scientist at the Centers for Disease Control, recited the list of chemicals in Atlanta's environment as if she were reading the names of old friends, ticking off diltiazem (brand name Cardizem, a heart drug), metformin (aka Glucophage, for diabetics), gemfibrozil (i.e., Lopid, another heart drug). Nobody was surprised.

Out in the aquatic environment, she noted, the CDC found eight antibiotics: trimethoprim, sulfamethazine, sulfamethoxazole, sulfadimethoxine, erythromcyin, roximthromycin, lincomycin and enrofloxacin. "Detection of antibiotics in raw drinking water is of particular concern," said Moll, "because the presence of these chemicals in the environment may lead to the development of resistant bacterial strains, thus diminishing the therapeutic effectiveness of antibiotics."

As Moll went on to say, some of the antibiotics detected were Class 1 drugs, meaning physicians typically fall back on them when other antibiotics don't work. Why might other antibiotics be ineffective? No controversy there: general overuse of antibiotics by physicians and farmers. But the sheer number of different antibiotics in the water supply, not to mention that every broad category of antibiotics has been detected, make the water an important new way for us to help dangerous bacteria develop ways to kill us even faster than they could on their own.

Roderick Mackie, a researcher at the University of Illinois whose work was not presented at the conference, has shown that resistant bacteria from one hog farm can spread, via natural drainage processes, to another hog farm 300 yards away. Biologists have also been finding widespread antibiotic resistance in prominent waterways like the Rio Grande as well as obscure ones in agricultural states like Iowa and Illinois. Because different species of bacteria can swap genes for resistance, even a little antibiotic in water could allow the bugs to develop defense mechanisms that will prove fatal to ailing people later.

And if less-effective antibiotics were not bad enough, there is a second reason to worry about drugs in our water. Traces of a variety of steroids, not to mention industrial and household products, may be interfering with delicate, exquisitely vulnerable hormonal receptors in all living creatures. These receptors are key cellular switches that are especially important during any organism's early development.

In the laboratory and in nature, man-made estrogen "mimic-molecules" are believed to be disrupting embryonic organisms across many species, even causing neurological and reproductive birth defects. Could the water supply be helping to distribute the estrogen mimic-molecules? Water engineers, for the record, are not worried. The American Water Works Association declined to speak to me but is on record that nothing is awry: "The occurrence of endocrine-disrupting chemicals in potable and nonpotable water has not been established."

Scientists in Minneapolis presented abundant evidence to the contrary. For one thing, most farmers liberally dose pigs, cows and chickens with hormones. Those male and female hormones are definitely reaching the environment in both liquid and solid animal wastes. Birth control drugs, even steroids used by body builders and pro athletes, are making similar deposits. The question is what effects the chemicals are having, and whether the water (or something else) might be the source.

One new clue came from the Mississippi River, where James Levitt of the University of Minnesota studied a variety of fish coping with endocrine mimic-molecules. Levitt compared walleyed pike upstream from a lock, where there were no endocrine mimic-molecules, with fish caught downstream from the lock, where there was plenty of sewage effluent and no shortage of estrogen disrupters. The male fish swimming in the dirty water had no sperm, and malformed testes. The female fish in the same water had similarly degenerated ovaries.

Should we care about walleye? Are their gonads the proverbial canaries in the coal mine? Some scientists think so. Researchers point to a large number of other water-dwelling creatures that are having similar problems. Alligators, carp, otters and other aquatic creatures are increasingly prone to disturbing defects or illnesses in their reproductive tracts. Why? The link to drugs and other industrial effluvia is tantalizing, circumstantial -- but controversial.

For years physicians have been arguing about sharply falling human sperm counts (in England's Thames River, these have been directly linked to water supplies). There are rising numbers of breast and uterine cancers, and hypospadias, a grisly birth defect of the urethra and penis. But the scariest element of the endocrine disrupter story was never explicitly mentioned in Minneapolis. The water specialists never quite brought themselves to say that some of the estrogen-mimic effects can be engineered in the laboratory by vanishingly small doses of chemicals like ethinyl estradiol, the key ingredient in birth control pills. Scientists are finding ethinyl estradiol in water at levels that are not all that different from those that cause untoward effects in the lab. You don't need big, easily detected doses to get significant changes.

So what's the bottom line? How freaked out should an ordinary citizen be? The best answer so far: Be aware but don't panic. That was the word from a scientist at the federal agency leading the way in analyzing drugs in the water: the U.S. Geological Survey (USGS) -- an agency that has long had scientists tramping around and investigating American streams and rivers.

Carefully avoiding the question of whether the drugs and other chemicals in water present any danger to human health, the USGS brought a lot of know-how to Minneapolis. Its impact was exceeded only by a platoon of German scientists (the world leaders in this field). Dana Kolpin, the lead author of the most eagerly awaited USGS paper, was not at liberty to discuss much of his data -- it's under wraps pending publication in a journal -- but Kolpin still gamely agreed to try to put the problem in perspective.

"I wouldn't get terrified," he says. "We're not trying to scare people." As he and other scientists at the meeting repeatedly reminded me, you'd have to guzzle thousands of gallons of the dirtiest water in America to get enough of a drug to constitute a single dose.

Kolpin's forthcoming article will analyze water samples from 141 American rivers. The USGS went looking for five broad classes of antibiotics, over-the-counter antacids, birth-control medicines, warfarin, codeine, insecticides, Prozac and Paxil, Advil and Tylenol -- even the ingredients that give colognes their musky odor and detergents their bubbly qualities. The compounds are found in every medicine cabinet, every cleaning closet, every supermarket. You're using this stuff. So am I.

But the data could be eye-opening. One hint Kolpin dropped was that of the 95 compounds the USGS researchers went looking for, they found 75. Eighty percent of the streams sampled had at least one compound. "It wasn't just finding one compound," Kolpin told his peers. "We need to look at mixtures and multiple compounds."

The prevalence of multiple compounds could turn out to be one of the stickiest questions. To what degree does long-term exposure to a lifelong cocktail of these chemicals differ from drinking separate doses of each contaminant? Existing federal water rules apply to one chemical at a time. But Christian Daughton of the U.S. EPA points out that there are so many similar mixtures in the water that they could present different cumulative risks. These might be similar to the elderly nursing home resident who takes nine different pills from four different doctors. One pill, two pills might have negligible effects. "But if you add them together, they could have an adverse effect," says Daughton, chief of the Environmental Chemistry Branch in the EPA's National Exposure Research Laboratory in Las Vegas.

As if the antibiotic and hormone issues weren't enough, Daughton notes a third potential issue with drugs in the water. They could be affecting universal cellular housekeeping common to all forms of life. These ensure that cells protect themselves, communicate and maintain equilibrium. So drugs in the water might disrupt serotonin pathways, or cellular efflux pumps, biological sentries that admit or remove foreign compounds.

"Drugs could inhibit these pumps," suggests Daughton, explaining that the pumps might lose their ability to flush out toxins. "If you take a wide variety of pollutants, and each one has an ability to inhibit these pump systems, their cumulative effect could be noticeable. ... Now all things that are toxic can go inside. An environment that did not used to be toxic can become toxic, because of the chemical that broke the camel's back."

Like all scientists, Daughton immediately hesitates and argues that chemists, biologists and toxicologists really need more time to unravel the evidence. He gracefully professes his own ignorance. "The truth of the matter," he says, "is that not much is known. The more you uncover, the more you discover, the more questions you generate. And you get further and further from where you want to be."

Such uncertainty (as with global warming) will be the main roadblock to any cleanup. At present, the Food and Drug Administration, Environmental Protection Agency and Department of Agriculture are all doing little to minimize drugs in the water supply. Even in the same agency, much less between agencies, the science people do not regularly converse with the regulatory people.

A few of those agencies did send smart researchers to Minneapolis, but their speakers typically presented inconclusive data or listed loophole after loophole, exemption after exemption. In short, they explained why they would have to study the problem for a few more decades -- or why existing regulations have effectively tied their hands from ongoing monitoring or lower limits.

Federal officials, to be fair, are guided by law (and haunted by long-forgotten epidemics like typhoid) to preoccupy themselves with infectious agents in water. The drugs-in-the-water scenario is too new and too murky to land high on their priority list. Locally, city by city, water managers have tight budgets already, and they've got other contaminants to worry about: arsenic, cryptosporidium, MTBE, all well-established hazards.

If the government did mobilize itself and propose limiting drugs in the water supply, local water managers would howl in protest. And the chemical and pharmaceutical industries will be prepared. There are already a number of Web sites and marketing campaigns defending the presence of trace-level amounts of water pollutants like phthalates and nonylphenols.

One of the most eloquent speakers in Minneapolis, a drug company vice president, argued that the pharmaceutical industry has already given the federal government all the data it will ever need about the environmental fate of its products. "There is no regulation that requires new studies to be undertaken," he told the scientists. All the relevant information is already in FDA files, he explained. Unfortunately for environmentalists and scientists trying to figure out what drugs do in the environment, most of the data is proprietary, safely locked away in FDA vaults.

Even imagining a cosmic political shift -- a realignment after which environmentalists wrestled the drug and chemical companies into submission -- the do-gooders would still have an insurmountable hurdle. They would have to contend with doctors and farmers and soccer moms who love their drugs, their hormones, their cleaning products. Would you want to give up your favorite deodorant? What if the best medicine for your toddler had to be withdrawn to protect the damned environment? We are what we pee. The 281 million citizens of the United States are going to be peeing (and then drinking) each other's medicines and personal care products for the foreseeable future.

One final point for anyone considering bottled water as an alternative to a tainted drinking water supply. Water chemists have analyzed thousands of samples over the years. Their tests take weeks or months to run, using expensive equipment that didn't exist 10 years ago. Those guys roll their eyes at the mention of bottled water. Twist their arms, and they whisper that the bottled water industry is lightly regulated at best, and usually draws its product from the same municipal water supplies you're already swallowing.

It could be worse. You could be a fish.

About the writer
Mark D. Uehling writes about science. He periodically sends trace levels of Allegra and Advil to water treatment engineers in Chicago.