Plastic Debris Is Getting Into The Great Lakes, Our Drinking Water, And Our Food

May 6, 2021

There’s been a lot of news about the amount of plastic debris in the oceans. But plastic pollution is also affecting the Great Lakes. A study out of the Rochester Institute of Technology estimates 22 million pounds of plastic debris enters the Great Lakes from the U.S. and Canada each year.

Lynn Knopf with Duck Creek Watershed Assembly snaps a photo of some of the volunteers who showed up to pick up trash at Duck Lake State Park along Lake Michigan.
Credit Lester Graham / Michigan Radio

The sky is blue and the Lake Michigan water is beautiful, but it’s windy and a bit chilly. Volunteers are gathering at the Duck Lake State Park north of Muskegon.

They’re listening to instructions about picking up trash on the beach and along a channel which connects Lake Michigan and Duck Lake. They’re asked to keep track of the kind of trash and later it’s to be weighed.

Usually, much of the trash is found on the big lake’s beach. Because of high lake levels, more of it has been deposited along the channel that connects it with Duck Lake. A lot of that trash is deteriorating plastic.

“It just crumbles into little, little tiny pieces and eventually it just becomes almost impossible to pick up,” said Lynn Knopf, chair of Duck Creek Watershed Assembly. She’s leading this event.

This clean-up is part of the Alliance for the Great Lakes Adopt-a-Beach program which organizes these events across the Great Lakes. In a typical year, 15 thousand people volunteer at one of a thousand events.

“Consistently, we see that about 85 percent of the litter picked up at Adopt Beach cleanups is made up of plastic,” explained Jennifer Caddick, the spokesperson for the Alliance.

Volunteers worked to pick up plastic trash like this on the Lake Michigan beach (in the distance) and along a channel leading to Duck Lake.
Credit Lester Graham / Michigan Radio

At Duck Lake, there were thousands of pieces of plastic ranging from shopping bags, to plastic forks and spoons and drinking straws. There were also lots of unidentifiable bits of plastic in the water and on the shore.

“We know that plastic pollution never goes away, right, it just breaks down into smaller and smaller pieces,” Caddick said.

The sun, heat, wind, and wave action work on the plastics, making them brittle. It gets to the point that bits of plastic are about the size of a grain of sand or smaller.

Not only is it unsightly trash on Great Lakes beaches, but the plastic can hurt wildlife.

“There's definitely a lot of wildlife rescue centers that repeatedly get calls for wildlife that may be entangled in fishing line or plastic rings, but for the small stuff, the microplastic debris, the primary focus there has been on the wildlife eating the microplastic debris,” said Sarah Lowe, the Great Lakes regional coordinator for the National Oceanic and Atmospheric Administration’s Marine Debris Program.

Wastewater treatment plants are not designed to filter out all microplastics such as microfibers. As washing machines clean clothes, such as your favorite fleece made from plastic fibers, many of those fibers ultimately find their way into rivers.

Lowe says researchers are taking a closer look at the tiniest microfibers in nature. They’re the primary type of microplastic being found in fish stomachs.

Scientists are finding some plastic is even becoming part of the fish.

“As our research methods become more sophisticated, we're able to look at smaller and smaller size ranges and we're finding that they're more abundant on the smaller scale,” said Mary Kosuth, a PhD student at the University of Minnesota’s School of Public Health and Environment Health Sciences.

Researchers are now finding plastic microfibers so small, they’re actually in the tissue, the flesh of fish. That means people are eating plastic too.

Researchers are also finding the plastic particles attract chemicals toxic to organisms at the bottom of the food chain as our partners at Great Lakes Now found in this story.

It’s not the only way you’re ingesting plastics.

Kosuth’s own research sampled tap water in several cities in the Great Lakes region and also sampled beer. She found plastic fibers in both the water and the beer. But something was off. In some cases she found greater amounts of microfibers in the Great Lakes beer than in the water used to make it.

“And (I) found no correlation between the amount that was in the tap water and the amount that was in the beer from, say, the same cities.”

Experts speculated the microfibers might be coming from clothing the workers were wearing or some kind of packaging. What Kosuth didn’t realize is that a lot of grain used by brewers comes in bags made of woven threads of polypropylene, a strong plastic.

Bags of grain used in brewing are often made of woven polypropylene, a strong plastic. Plastic microfibers from the bags might be getting into the beer of Great Lakes breweries.
Credit Lester Graham / Michigan Radio

At Griffin Claw’s brewery in Rochester Hills, the head brewmaster and head distiller Dan Rogers hadn’t heard about plastic in the water or the beer.

But, there were pallets of plastic sacks of grain and larger so-called super-sacks or bulk bags in the brewery. The question was if it made any sense to suspect the bags used to ship grain.

“Yes, it does, a lot of these malts are put in woven bags, it's like a fabric almost. And some of the bags we have, they’re paper, but on the inside, there's a plastic liner for like a moisture barrier. So, I would say all this grain touches plastic,” Rogers said.

He said he’d start investigating to see what should or could be done at his brewhouse.

Dan Rogers is the head brewmaster and head distiller at Griffin Claw Brewing Company. He says it's plausible that plastic grain bags might be partially responsible for plastic microfibers getting into Great Lakes beer. He intends to look into the matter.
Credit Lester Graham / Michigan Radio

As for microfibers in tap water, treatment plants are not yet set up to filter out all these microscopic threads of plastic. One study found even catching 95 to 99 percent of the fibers means tens of millions of plastic microfibers can still get into drinking water each day at a typical plant. They’re just too small to catch them all.

Single use plastics are pervasive. Some, such as medical devices, are necessary. Plastic packaging is used to prevent retail theft. Some fleeces and other clothing are made of plastic and shed microfibers.

Lynn Knopf says years of picking up plastic trash along Lake Michigan has made her aware that personal choices make a difference.
Credit Lester Graham / Michigan Radio

Lynn Knopf stopped picking up trash at Duck Lake State Park for a bit to talk about the problem. Since seeing the mess on the beaches firsthand, she’s dedicated to cleaning up what she can and thinking before she buys things.

“You know, it's something each person has to really look at themselves and decide what the best thing is they can do, but, you know, it all comes down to education and, you know, wanting to make the world a better place, I think.”

Some environmentalists say manufacturers are going to continue to make and sell single use plastics as long as there’s a market. They want the public to put pressure on businesses that make and sell single-use plastic products. They insist we have to find ways to prevent those millions of pounds of plastic getting into the Great Lakes and your water, and your beer.

The Great Lakes News Collaborative includes Bridge Michigan; Circle of Blue; Great Lakes Now at Detroit Public Television; and Michigan Radio, Michigan’s NPR News Leader; who work together to bring audiences news and information about the impact of climate change, pollution, and aging infrastructure on the Great Lakes and drinking water. This independent journalism is supported by the Charles Stewart Mott Foundation.