Down drain, they remain
http://www.startribune.com/stories/462/5083855.html
by Tom Meersman
Mpls Star Tribune
Published November 14, 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 the state.
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' sources.
"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 Control Agency.
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 emerging contaminants.
Drinking water
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 Department.
"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 taken elsewhere.
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 adhesives.
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
http://www.startribune.com/71
Tom Meersman is at meersman@startribune.com |