From The New York Times -
Scientists Turn Their Gaze Toward Tiny Threats to Great Lakes
By JOHN SCHWARTZ
NORTH EAST, Pa. — The newest environmental threat to the Great Lakes is very, very small.
Tiny plastic beads used in hundreds of toiletries like facial scrubs and
toothpastes are slipping through water treatment plants and turning up
by the tens of millions in the Great Lakes. There, fish and other
aquatic life eat them along with the pollutants they carry — which
scientists fear could be working their way back up the food chain to
humans.
Scientists have worried about plastic debris in the oceans for decades,
but focused on enormous accumulations of floating junk. More recently,
the question of smaller bits has gained attention, because plastics
degrade so slowly and become coated with poisons in the water like the
cancer-causing chemicals known as PCBs.
“Unfortunately, they look like fish food,” said Marcus Eriksen, executive director of the 5 Gyres
organization, speaking of the beads found in the oceans and, now, the
lakes. His group works to eliminate plastic pollution.
Studies published in recent months have drawn attention to the Great Lakes, where there may be even greater concentrations of plastic particles than
are found in oceans. The National Oceanic and Atmospheric
Administration has also been looking at the impact of microplastics on
marine life.
In recent months, major cosmetics companies including Johnson & Johnson, Unilever,
and Procter & Gamble have pledged to phase out the use of the beads
in favor of natural alternatives, though they say the shift could take
two years or more. The Johnson & Johnson statement says, in part,
“Our goal is to give consumers peace of mind that our products are
gentle on people and gentle on the environment.”
Johnson & Johnson, along with others, has questioned whether the
spheres are actually getting through wastewater treatment plants. So Sherri A. Mason,
an environmental chemist at the State University of New York in
Fredonia, has spent the past two summers trolling the Great Lakes with a
fine-mesh net that has a broad mouth for skimming surface waters.
Working with students aboard the historic brig Niagara, Dr. Mason has
collected more than 100 samples, which her students examine minutely for
beads and other debris. They sort out the plastics from bits of fly ash
and other products from power plant smokestacks and, using electron
microscopes to compare the spheres with those from commercial products,
have found them to be similar in shape, size and composition.
(Sandblasting uses small beads as well, but they tend to be more dense
than the beads in consumer products, and sink.)
In a recent paper,
Dr. Mason and colleagues took samples that suggested concentrations of
as much as 1.1 million bits of microplastics per square mile in some
parts of the lakes’ surfaces, with beads making up more than 60 percent
of the samples. She has found beads in all five of the lakes, with the
greatest concentrations in Lakes Erie and Ontario, which take the water
flows from the other lakes and which are ringed with cities and towns.
While many of the beads appear to enter the environment when storms
cause many wastewater treatment plants to release raw sewage, it is
increasingly clear that the beads slip through the processing plants as
well, Dr. Mason said at a sewage treatment plant in North East, a town
near Erie.
She visited the plant to see if she could find beads in the clean water
flowing from the plant at the end of the treatment process, after the
removal of the organic solids that sat ripely in large containers bound
for a landfill.
Mike McCumber, a supervisor at the plant, challenged her: “You ain’t
going to find nothing!” But he helped her set up a pump to flush the
water through fine screens, and after less than a minute, she had
scraped a pearlescent sphere off the mesh.
“Hey, Mike! I think I got a bead,” she told him.
“Oh, boy,” he responded in defeat.
She was quick to point out that the sewage treatment plant is not
designed to capture the tiny beads, which vary in size but are about as
big as a period on a newspaper page. “It’s not a design problem with the
system,” she said. “It’s a design problem with the product.”
Scientists are still working through the links of the chain leading back
to humans; about 65 million pounds of fish are caught in the Great
Lakes each year. Worldwide, the beads have been found in some marine
organisms and not in others, and the transfer of poisons from the beads
into the bodies of the creatures that eat them is still being
established.
It has been shown to happen in lugworms,
which live in the North Atlantic, and Dr. Mason said, “If it happens in
lugworms, there’s a pretty good chance that it’s happening in other
species.”
Lorena Rios Mendoza, an assistant professor of chemistry at the
University of Wisconsin-Superior, said that the bits of plastic have a
great capacity to attract persistent pollutants to their surface, and
that the Environmental Protection Agency has classified some of those
compounds as priority pollutants that can interfere with human
physiology.
“Plastics are not just acting as mimic food, but they can also cause
physical damage to the organism,” she said. She has examined fish guts
and found plastic fibers — possibly from the breakdown of synthetic
fabrics through clothes washing — that are laden with the chemicals, and
said she expected to find beads as well.
Some producers of natural facial products have found alternatives to the
inexpensive plastics — some of which can sound less like a cleanser
than a variety of Whole Foods granola. St. Ives, a Unilever brand, uses
natural exfoliants like ground walnut shells. A spokeswoman for Burt’s
Bees said the company had never used the plastic; its acne scrubs use
jojoba beads, and its citrus facial scrub is made with “oat kernel
flour, almond meal and pecan shell powder.”
Dr. Mason applauded the use of alternatives, because there is no getting
rid of the beads that are already in the water. Any attempt to skim the
waters of the lakes to try to filter them out would scoop up plankton
and other essential parts of the food chain, Dr. Mason said: “You’d be
killing all the living necessary aspects of the ecosystem at the same
time you’re trying to extract the plastic.”
So the answer to the problem of the tiny beads is to limit their use, she said. “We need to stop putting it out there.”
http://www.nytimes.com/2013/12/15/us/scientists-turn-their-gaze-toward-tiny-threats-to-great-lakes.html?pagewanted=all
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