90% of Great Lakes Contains Microplastics, Study Finds

What's the story?

• A new report found that 90% of Great Lakes water samples taken over the last decade contain microplastic levels that are unsafe for wildlife. The highest median levels were found in Lake Michigan and Lake Ontario.
• The Great Lakes provide drinking water to over 40 million people in the U.S. and Canada. They contain roughly 90% of the U.S.’s fresh water and are home to 3,500 species of plants and animals.

The scale of the problem

• Microplastics have been found in fish consumed by humans and beer brewed with Great Lakes water. Scientists are researching whether microplastics act as "sponges," soaking up other toxins in the water and compounding the danger when consumed by wildlife.
• The U.S. Geological Survey found that there are 112,000 particles of microplastics per square mile in the Great Lakes. 
• Western University discovered that there are so many microplastic particles at the bottom of the lakes that they are becoming a permanent part of the sedimentary layer. Patricia Corcoran, a sedimentary petrologist, said future geologists will be able to find them in the rock layer:

“They’ll be a marker on the sedimentary horizon. We’ll be known as that horrible group of humans who did this.”

• The main contributors to the pollution are wastewater treatment plants, microfibers shed from clothing in washing machines, and plastic pellets used in manufacturing. 

Possible solutions

• The scientists argue that the risk can be mitigated with government cooperation and monitoring programs. The Great Lakes Water Quality Agreement already monitors for other pollutants and could be expanded. 
• Solutions like washing machine filters and storm sewers at manufacturing sites could also be more widely promoted. Chelsea Rochman, a microplastics researcher, said:

"In the city of Toronto, we estimate as many as 23 to 36 trillion microfibers may be emitted to Lake Ontario watersheds each year.”

Is the government doing enough to monitor microplastics?

—Emma Kansiz 

(Photo credit: iStock/Uladzimir Zuyeu)