TRAVERSE CITY,
Mich. (AP) — Scientists who have reported that the Great Lakes are awash
in tiny bits of plastic are raising new alarms about a little-noticed form
of the debris turning up in sampling nets: synthetic fibers from garments,
cleaning cloths and other consumer products.
They are known as
"microfibers" — exceedingly fine filaments made of petroleum-based
materials such as polyester and nylon that are woven together into
fabrics.
"When we launder
our clothes, some of the little microfibers will break off and go down the
drain to the wastewater treatment facility and end up in our bodies of
water," Sherri "Sam" Mason, a chemist with the State University of New
York at Fredonia, said Friday.
The fibers are so
minuscule that people typically don't realize their favorite pullover
fleece can shed thousands of them with every washing, as the journal
Environmental Science & Technology reported in 2011.
Over the past
couple of years, Mason and colleagues have documented the existence of
microplastic litter — some too small to see with the naked eye — in the
Great Lakes. Among the particles are abrasive beads used in personal care
products such as facial and body washes and toothpastes. Other researchers
have made similar finds in the oceans.
A number of
companies are replacing microbeads with natural substances such as
ground-up fruit pits. Illinois imposed a statewide ban on microbeads last
year. Similar measures were proposed in California and New York.
But microfibers
have gotten comparatively little attention. They've accounted for about 4
percent of the plastic litter that Mason and her students have collected
from the Great Lakes. The group drags finely meshed netting along the lake
surfaces, harvesting tens of thousands of particles per square mile, and
study them with microscopes.
About
three-quarters of the bits they've found are fragments of larger items
such as bottles. Smaller portions consist of microbeads, Styrofoam and
other materials.
But when Mason's
team and a group from the Illinois-Indiana Sea Grant program took samples
from southern Lake Michigan in 2013, about 12 percent of the debris
consisted of microfibers. It's unclear why the fibers were three times as
prevalent in that area as elsewhere in the lakes, although currents and
wave actions may be one explanation, said Laura Kammin, pollution
prevention specialist with Sea Grant.
Ominously, the
fibers seem to be getting stuck inside fish in ways that other
microplastics aren't. Microbeads and fragments that fish eat typically
pass through their bodies and are excreted. But fibers are becoming
enmeshed in gastrointestinal tracts of some fish Mason and her students
have examined. They also found fibers inside a double-crested cormorant, a
fish-eating bird.
"The longer the
plastic remains inside an organism, the greater the likelihood that it
will impact the organism in some way," Mason said, noting that many
plastics are made with toxic chemicals or absorb them from polluted water.
She is preparing a paper on how microplastics are affecting Great Lakes
food chains, including fish that people eat.
There's also a
chance that fibers are in drinking water piped from the lakes, she said.
Scientists reported last fall that two dozen varieties of German beer
contained microplastics.
Because
microfibers are used so widely, there's no obvious solution, Mason said.
Persuading people to stop wearing synthetic clothes likely would be a
tougher sell than the idea of switching facial scrubs.
But pollution
prevention remains the best way to protect the lakes, Kammin said.
"It's very hard
to remove these microplastics once they're out there," she said.