TINY bits of plastic are emerging as a threat to the United States’ Great Lakes. Large quantities of round pellets, mainly from health and beauty products, were among the plastic pieces researchers found in 2012 in Lake Erie, Lake Superior and Lake Huron.
In fact, some of the Lake Erie samples had more plastics than have been found in ocean samples.
“The levels were astronomical ... and that’s troubling,” said Sherri A. Mason, an associate professor of chemistry at the State University of New York at Fredonia, who led the study. The discovery has ramifications for the Great Lakes and for people living around them, she said.
The continuing research is the first look at plastics in the Great Lakes and the second look at plastics in freshwater in the world. Plastics in the oceans have been studied since 1999.
The main source of the microplastics in the Great Lakes appears to be tiny scrubbing beads added to personal care products, such as scrubbing facial washes and toothpastes.
Two companies, Proctor & Gamble and Johnson & Johnson, have said that they will stop using spheres of polyethylene in their beauty products by 2017.
In 2012, Mason’s team collected water samples at 21 sites on the three lakes. About 90% of the almost-microscopic plastics found that summer were from Lake Erie. Additional samples were collected this summer on Lake Erie, Lake Michigan and Lake Ontario and the adjoining St. Lawrence River – with about 135 samples collected. The results of this year’s sampling won’t be completed until next spring.
The earlier results surprised Mason’s team. The researchers did not expect to find such concentrations of plastics and had not expected the pieces to be so tiny.
One water sample from Lake Erie contained 1,100 bits of plastic floating in it, a number that shocked researchers. The concentrations were equal to 450,000 bits of plastic per square kilometre in eastern Lake Erie, she said.
The pieces of microplastics are generally from one-third of a millimetre to 1mm. Mason said 60% the microplastics found floating in Lake Erie in the 2012 sampling were perfectly spherical balls of plastic. Such beads are so tiny that they go from home drains through sewage treatment plants into rivers that empty into the lakes. Also found in some Lake Erie samples were fly ash and coal ash from coal-burning power plants, she said.
It is unclear how great a threat such plastics pose to the Great Lakes and its ecosystems, Mason said. Much more research will be needed to answer that question, but the issue is seen as an emerging cause for concern.
Fish and aquatic insects might eat the plastic beads, and the bits could be inside fish humans are consuming, Mason said.
It is also uncertain how long it might take the plastics to degrade and whether they are sinking to the bottom.
They can absorb toxic chemicals in the water and might serve as rafts for tiny micro-organisms, including bacteria, that could be dangerous to humans. – Akron Beacon Journal/McClatchy Tribune Information Services