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St. Paul, Minn.--Two studies released today by the Minnesota Pollution
Control Agency (MPCA) confirm that a wide variety of unregulated chemicals are
ending up in Minnesota’s lakes and rivers.
The chemicals, including pharmaceuticals and personal care products, are
of concern because many have properties that can interfere with the functioning
of hormones in animals and people.
Previous studies have shown the chemicals are often found in
streams that receive wastewater discharges.
Limited sampling has also revealed that they are often found in lakes,
which do not typically receive wastewater. But the number of lakes and rivers included in
those investigations was not large enough to give an accurate picture of the extent
of the contamination. The two latest studies provide statistical evidence of just
how widespread the chemicals are in Minnesota’s surface waters.
“What these studies really are measuring is the footprint of
our society and how we live,” said MPCA Commissioner John Linc Stine. “Our
lakes and rivers are reflecting the chemicals we use and put into our bodies.
These chemicals have very beneficial uses, but unfortunately they tend to stick
around in the environment after their first use.”
In the two studies, the MPCA in 2010 and 2012 sampled lakes
and rivers using funds from the state of Minnesota and the US Environmental
Protection Agency, part of nationwide EPA surveys to find out what’s in the
nation’s waters.
For the lakes study, 50 lakes were randomly selected across
Minnesota. Samples were collected and analyzed for 125 chemicals. The study included
analysis of “endocrine-active compounds” (EACs), so called because they mimic
or interfere with the actions of naturally occurring hormones. These chemicals
can have adverse effects on aquatic ecosystems and fish.
Results of the lake study were generally consistent with
findings of previous but smaller studies that found commonly used chemicals widely
distributed in Minnesota lakes. The insect repellent DEET was found in 76% of
the lakes sampled, making it the most frequently detected chemical. Chemicals not previously analyzed – including
cocaine, the antidepressant amitriptyline, and the veterinary antibiotic
carbadox – also were often detected in the lakes.
MPCA officials said the detection of cocaine was unexpected,
one for which they couldn’t account except that other studies have shown it can
attach to fine particles and might be transported long distances through the
atmosphere.
The rivers study analyzed 18 chemicals, including several pharmaceuticals
and personal care products, and was conducted at 150 river locations selected
at random. Parabens, a family of
chemicals used as preservatives for food and cosmetics, were commonly found,
with methylparaben detected in over 30% of the samples. A breakdown product of the
corrosion inhibitor benzotriazole was found in 12% of the samples. Carbamazepine, used in medications to treat
attention deficit hyperactivity disorder, and several antidepressants were also
found.
Many of the chemicals in the MPCA studies were detected at
very small concentrations, in the low parts per trillion. Such levels are of concern because EACs have
the potential to adversely affect fish and other aquatic organisms even at
extremely low levels.
One part per trillion is roughly equivalent to 1 drop in a
pool of water covering the area of a football field 43 feet deep.
The MPCA plans to continue testing surface waters for
pharmaceuticals and EACs on a rotating five-year basis to identify any trends
that may be occurring.
Reports on the studies and summary information are available
on MPCA’s webpage at http://www.pca.state.mn.us/iryp8f4. The two reports are titled "Pharmaceuticals and Endocrine Active Chemicals in Minnesota Lakes" and "Pharmaceuticals and Personal Care Products in
Minnesota’s Rivers and Streams".
Broadcast version
From bug spray to illegal drugs, a wide variety of chemicals
from prescription medicines and personal care products are ending up in
Minnesota’s lakes and rivers, according to a State study.
In the studies, the Minnesota Pollution Control Agency
randomly sampled lakes and rivers for chemicals used in pharmaceuticals and
products like soaps and shampoos. The
mosquito repellent DEET was the most often detected, along with chemicals used
in antidepressants and antibiotics.
Cocaine also showed up frequently.
MPCA officials said they didn’t know why, except that cocaine can be
carried long distances through the atmosphere and fall to earth with rain and
snow.
The chemicals were all detected at very low concentrations,
in the low parts per trillion. One part per trillion is equal to one drop of
water in pool the size of a football field covered with water 43 feet
deep. But, the MPCA says, the findings are concerning because even at low levels, several of the chemicals are known to interfere with
hormone function in fish and other aquatic organisms.
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The mission of the MPCA is to work with Minnesotans to protect, conserve and improve our environment and enhance our quality of life.
St. Paul • Brainerd • Detroit Lakes • Duluth • Mankato • Marshall • Rochester • Willmar
www.pca.state.mn.us • Toll-free and TDD 800-657-3864
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