U.S. Water News Online
WASHINGTON -- A government analysis shows the nation's
waterways are awash in traces of chemicals used in beauty aids,
medications, cleaners and foods.
Among the substances: caffeine, contraceptives, painkillers,
insect repellent, perfumes and nicotine.
Scientists say that the problem is that these substances largely
escape regulation and defy municipal wastewater treatment. And the
long-term effects of exposure are unclear, they say.
The compounds are sold on supermarket shelves and found in
virtually every medicine cabinet and broom closet, as well as farms
and factories. And they are flushed or rinsed down the drain every
day. But they do not disappear, researchers warn.
Hydrologists with the U.S. Geological Survey tested water samples
in 30 states for 95 common compounds, an emerging class of
contaminants known as pharmaceutical and personal care pollutants, or
The scientists found that the chemicals persist in the environment
in concentrations as low as one part per billion or less. The results
mirror similar studies of PPCPs in Europe and Canada.
Yet little is known about PPCPs' potential health and
environmental effects. The use and disposal of 81 of the 95 compounds
in the study are entirely unregulated, officials said.
"Compounds that we use in households or even consume can persist
though wastewater treatment and affect resources on a pretty broad
scale," said Herb Buxton, USGS coordinator of the USGS toxic
substances hydrology program.
For example, many scientists suspect the widespread use of
anti-bacterial agents in human medicines, household cleaners and
veterinary medicines has encouraged the development of germs that are
resistant to antibiotics.
The USGS study found at least 31 antibiotics and anti-bacterial
compounds in water samples. The study also tallied traces of at least
11 compounds linked to birth control and hormone supplements.
Some studies have linked environmental exposure to hormones to
deformed sex organs in wildlife, sex reversal in some fish and
declining fertility in humans, as well as cancers and other diseases.
Scientists who did not participate in the USGS survey said PPCPs
represent the "next big unknown" in environmental contamination.
Exposure to even tiny amounts may result in cumulative risks, they
said, especially when the compounds combine in unanticipated ways.
"You don't need therapeutic doses of a drug to have an effect,"
said Christian Daughton of the Environmental Protection Agency's
exposure research laboratory in Las Vegas. "Some organisms have
potential to suffer multigenerational exposures. Parts per billion
could have profound effects."
Industry and water utility officials said they expect the EPA to
decide in the next few years how to regulate PPCPs. They said
promising new wastewater treatment technologies can break down many
of the chemicals using biological methods, or even exposure to
"We're not ignoring it," said Alan Roberson, regulatory affairs
director for the American Water Works Association in Washington. "One
question is what do you do with the concentrated form of these
chemical compounds if you take them out of the water."
In 1999-2000, USGS scientists collected samples downstream from
cities, farms and factories. Many of the waterways contribute to
municipal water supplies.
They included the Sacramento River at Freeport, Calif.; the South
Platte River in Denver; the Mississippi River above Minneapolis/St.
Paul; and the Charles River in Boston. Seven or more chemicals were
found in half of the streams sampled.
In addition to caffeine, the USGS reported the most frequently
detected compounds were coprostanol and cholesterol, which are
byproducts of digestion. Also found frequently was DEET, a common
insect repellent. Among the medications found were the blood thinner
warfarin, antidepressants and blood-pressure medicine.
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