Drugs Contaminate Our Drinking Water
By Ron Seely
Experts Are Worried As Traces Of Common Medicines Are Found In Water Supplies.
Wisconsin State Journal : FRONT : A1 Sunday, August 29, 2004
Before you read any more of this story, go to your kitchen sink and draw a glass of water. Hold it up to the light and take a good look.
Take a sip.
And think about this. Researchers are finding that our drinking water may contain small amounts of the many drugs that line the shelves of most of our medicine cabinets.
In addition to that refreshing sip of water, you may be ingesting everything from the estrogen used in birth control pills to antibiotics and anti-depressants.
If you find that thought unsettling, you’re not alone. Agencies such as the federal Environmental Protection Agency and the Wisconsin Department of Natural Resources are investing millions of dollars in research aimed at measuring the levels of pharmaceuticals in our water supplies.
And those studies are turning up surprising levels of the chemical substances in lakes and streams, in the treated water coming from sewage treatment plants and, most disturbing, in the aquifers from which we draw our drinking water.
It’s not somebody else’s problem, either. Research has turned up pharmaceuticals in surface water, as well as in water coming from septic systems, right here in Dane County, according to Ken Bradbury, a hydrogeologist with the Wisconsin Geological and Natural History Survey who is studying the problem locally.
“It’s troubling,” said Bradbury. “It’s troubling that we may be drinking trace amounts of things we haven’t thought about as being there. We don’t know the health effects and we’re not doing enough monitoring to know what the levels are.”
Researchers are just beginning to look at the potential impact of such substances on our health.
There are numerous concerns. Some fear, for example, that exposure to antibiotics will worsen an already existing problem — the growing resistance of bacterial pathogens to antibiotics that are overused.
And studies of fish and other aquatic wildlife exposed to estrogen have turned up numerous problems — such as hermaphroditic fish downstream of sewage treatment plants in the United Kingdom.
Such studies have led some researchers to suggest that declining sperm counts as well as increasing rates of breast, prostate and testicular cancers in humans may be related to estrogenic compounds in the environment.
Henry Anderson, chief medical officer in the state’s Bureau of Environmental and Occupational Health, said much of the concern about potential health impacts stems from the nature of the drugs themselves.
“These are drugs that are designed to impact people,” Anderson said.
Such contaminants, considered one of the hottest emerging issues in environmental health, have already been tagged with an acronym. They’re called pharmaceuticals and personal care products, or PPCPs.
They come from a number of sources. Unwanted medications are frequently flushed down the toilet or washed down the sink. We all excrete ingested drugs every time we use the bathroom. When we wash our hands with antibiotic soap, we send antibiotics down the drain and into the waste stream. Farms where antibiotics are used to stimulate animal growth are also a source of contamination.
Lack of research makes it difficult to estimate the amounts of PPCPs entering our waters. Generally, drugs are showing up in much lower concentrations than better studied contaminants such as nitrates.
K.G. Karthikeyan is a UW-Madison faculty member in the Biological Systems Engineering Department who is researching the presence of drugs in water supplies. He pointed out that in both his studies and others, such substances are detected in parts per billion as opposed to contaminants such as nitrates, which are measured in parts per million.
But the sheer volume of pharmaceuticals used in this country and around the world leads most to suspect that the concentrations of drugs in our waters will only increase. Worldwide sales of pharmaceuticals is approaching $500 billion. Last year, people spent $26 billion on cholesterol and triglyceride reducers alone, an increase of 14 percent from 2002, making it the largest selling class of drugs, just ahead of ulcer medications and antidepressants.
That these drugs were making their way into our water first became apparent in Europe. About 10 years ago, environmental scientists found clofibric acid, a cholesterol-lowering drug, in ground water beneath a German sewage treatment plant.
In this country, the first comprehensive survey of PPCPs in the environment was conducted by the U.S. Geological Survey, which analyzed water samples from 139 streams across 30 states in 1999 and 2000. The streams were all downstream of crowded urban areas and large livestock farms. Pharmaceuticals and hormones were found in 80 percent of the streams sampled.
Since then, other tests have revealed extensive contamination of both ground and surface waters by pharmaceuticals. In short, everywhere researchers have looked, they have found the substances.
Scientists with the state Laboratory of Hygiene tested 105 surface and ground-water samples from around the country and found that 64 contained estrogenic compounds, although at low concentrations.
Researchers turned up more contamination in surface waters than in ground water, but reported that they were surprised to find that 42 percent of the ground-water samples tested were tainted with estrogen.
In their report, the scientists called that finding “striking” and concluded that “while the levels were generally lower than the surface water supplies, the fact that there were detections at all should serve as a heads-up.”
Bill Sonzogni, a researcher at the laboratory who supervised the research, said that while such research is in its earliest stages, the findings are enough to merit more study.
“I don’t think it’s a health hazard at this point,” Sonzogni said. “But it is something that needs looked at more . . . I think there certainly is concern at this point.”
In his studies, UW-Madison scientist Karthikeyan, working with a grant from the DNR, sampled waters for antibiotics at several treatment plants in Wisconsin, including Green Bay, Oshkosh, Lake Geneva, Barron-Cameron, Hayward, and Spooner.
At every site, according to his preliminary findings, antibiotics were detected in samples from waters both before and after treatment. At two plants, those in Lake Geneva and Spooner, antibiotics were found in adjacent ground-water monitoring wells.
Bradbury, with the Wisconsin Geological Survey, has been studying water in a new Sun Prairie subdivision that relies on septic systems to treat wastes. He and other researchers have detected ibuprofen, as well as estrogenic compounds, in water from the septic systems. Although ground water in the subdivision has been tested, no pharmaceuticals were discovered, Bradbury added.
All of this science has lots of implications, according to Anderson, for regulators such as the EPA as well as for the operators of treatment plants.
The problem for sewage treatment plants is that traditional methods of treating waste do not eliminate many of the pharmaceuticals or hormones.
Paul Nehm, director of operations and maintenance for the Madison Metropolitan Sewerage District, said tests have shown the presence of very low levels of pharmaceuticals in water both before and after treatment at the plant. But levels are considerably lower in water after treatment, he added, leading him to believe that processes used at the plant are filtering out some of the substances.
In research released last week, UW-Madison environmental chemist Joel Pedersen reported that studies of three California treatment plants showed traditional methods of treating waste weren’t as effective at filtering pharmaceuticals. Two of the plants studied used advanced treatments, such as reverse osmosis in which water is forced through a membrane that blocks passage of foreign molecules.
Of 19 contaminants studied, the traditional plant eliminated only five. Studies of the more advanced plants, however, showed one eliminated 16 and another eliminated 12 of the pharmaceutical and hormonal compounds.
Such science, according to Wisconsin’s Anderson, will eventually be important in deciding whether to require more treatment of waste water. As important, he added, are studies such as Bradbury’s of private septic systems which are even less effective at filtering drug wastes.
Anderson, at least, hasn’t missed the irony of the very drugs we use to try and improve our health coming back in our drinking water to potentially cause new health problems. And he points out that some researchers have actually raised the possibility that some of the drugs finding their way into our water supplies might be beneficial for us. Maybe some who are accidentally ingesting cholesterol-lowering drugs are better off, Anderson said.
But, mostly, scientists say that at this point the things we don’t know about drugs in our water far outnumber those things we do know.
“There are lots of questions,” concluded Karthikeyan.
Contact Ron Seely at email@example.com or 252-6131