Down drain, they remain
By Tom Meersman
The Star Tribune
Published November 14th, 2004
Shampoo, bug spray and that morning cup of java linger
in the environment after they're showered off or tossed
down the drain, according to the most extensive study
of Minnesota waters ever conducted.
Caffeine, synthetic musk used in personal-care products,
a flame retardant, an herbicide, the popular insect repellent
DEET and other pharmaceuticals, products and chemicals
are part of a complex brew being found in waters around
Little is known about the risk from everyday flushing,
dumping and pouring out of familiar chemicals that make
lives healthier, easier or at least more pleasant-smelling
-- especially at the low levels detected. Thirteen of
the chemicals, however, are known to disrupt the hormones
and sexual development of some fish or other animals,
the study found.
Scientists found 74 chemicals at 65 sites across the
state. The samples were taken from rivers and streams
near municipal water supplies and sewage treatment plants,
treated drinking water and water below landfills and livestock
lagoons. The study, by three government agencies from
late 2000 to 2002, did not attempt to identify the chemicals'
"Because they are a constant source, everyday aquatic
organisms are bathed in these compounds, and I don't think
anybody knows how that affects them," said Kathy
Lee, a hydrologist for the United States Geological Survey
(USGS) and chief author of the study.
The study, which cost $564,000, was presented at an international
water conference last month in Minneapolis. Other researchers
were from the Minnesota Health Department and Pollution
Many chemicals were found just downstream of four sewage
treatment plants at East Grand Forks, Rochester, Duluth
and St. Paul. The plants use various technologies to remove
contaminants in sewage and industrial waste, but traces
of many compounds get through.
At the metro plant in St. Paul, about 200 million gallons
of wastewater are treated each day, and released into
the Mississippi River. Like many plants, it removes metals
and several pollutants, but not many of the hormones,
pharmaceuticals and other chemicals flushed into toilets
or rinsed down drains.
"We're not designed to remove these chemicals, and
we're not the source of them," said Rebecca Flood,
environmental manager for the plant operated by Metropolitan
Council Environmental Services.
She said that detecting those compounds at such low levels
-- often in the parts per billion -- is cutting-edge research.
Flood said the council has supported research into the
Traces of some chemicals also were detected in intakes
of municipal water-treatment plants at Moorhead, East
Grand Forks, St. Cloud, Mankato, St. Paul and Minneapolis.
After the water was treated, it showed either no contaminants
or barely detectable levels, said Doug Mandy, manager
of the drinking water protection section for the Health
"From a health standpoint, we're fairly certain
that this is not a problem at the levels that we found,"
Mandy said. "But our concern is that these numbers
will continue to grow over time because people will continue
to use these items or products and they will continue
to enter the environment."
Studies elsewhere have found a similar chemical brew
in waters. Many of the compounds are not regulated as
water pollutants, although federal officials are considering
whether to set limits for some of them. The study did
not include some chemicals that previously have been found
in water and already have drinking water standards, such
as the weed-killer atrazine.
Leroy Folmar, a retired research physiologist for the
Environmental Protection Agency, said it's not surprising
that scientists with the latest equipment are detecting
dozens of compounds. "This is just the tip of the
iceberg," he said.
"When you are prescribed medication of some kind,
it is usually way more than your body requires, so it
is excreted and much of the drug or chemical ends up in
the sewage treatment plant," he said. Folmar said
drugs with sexual side effects eventually could become
a problem for drinking water quality downstream, and antibiotics
in the water may result in strains of bacteria that become
resistant to antibiotic treatment.
Another major concern arising from this and similar studies
is the effect of natural and synthetic hormones -- or
chemicals that mimic hormones -- on aquatic creatures.
In the mid-1990s, while studying carp and walleye in Minnesota,
Folmar found that male fish in the Mississippi just below
the metro sewage treatment plant were becoming "feminized."
Male fish had depressed levels of testosterone and were
producing a yolk protein normally made only by female
fish. Female walleye near the plant had five times the
normal levels of estrogen in their blood compared to those
Not going away
The detected chemicals are a persistent problem because
they are in products used to make life easier and keep
people healthier, but then are dumped into landfills or
flushed down the drain -- sometimes in vast quantities.
Even though some of the detected chemicals may degrade
quickly, the environmental problem doesn't go away because
more are added continually to the waters, said Fardin
Oliaei, emerging contaminants coordinator at the Pollution
Control Agency. She said that drugmakers and medical authorities
should reconsider their advice for consumers to flush
unused medicines down the toilet.
Another chemical found frequently in the state's waters
is a flame retardant widely used in foam for furniture,
cars and building insulation, and in various resins and
A pair of synthetic musks also detected frequently in
the study are used to mask scents or add fragrance to
shampoos, perfumes and household cleaners. Keri Hornbuckle,
associate professor in civil and environmental engineering
at the University of Iowa, said that at least a million
pounds of the chemicals are used in the United States
each year. They degrade slowly to give products long shelf
lives, she said.
"You'd be hard-put to find someone who doesn't use
these chemicals in some personal care product," said
Hornbuckle, whose own research found the fragrance in
Lake Michigan. "It's amazing that we're releasing
such large quantities of them every day, yet we have almost
no information about their potential costs to the environment."
To learn what's in specific waters, read the study at
Tom Meersman is at email@example.com.