Delving Deeper into Great Lakes Microplastics
What we know and the possible solutions to get plastic out of the Great Lakes
Microplastics are a common problem in our oceans, lakes, and rivers. We know that most plastic that ends up in our oceans comes from freshwater sources, like rivers and lakes. But how much plastic is in the Great Lakes, and how do we stop it?
Some researchers surmise that microplastics in the Great Lakes pose a more significant problem than plastic in our oceans. One of the big reasons for this claim is that plastic in the Great Lakes has nowhere to go. Once it settles into the lake bed or in algae, it is there to stay. Microplastics are also beginning to find their way into the water and food sources for millions of people in the Great Lakes region.
What are microplastics, and how extensive is the problem
Microplastics are tiny fragments broken down from humans’ use of plastic. We are all aware of the problem through media coverage. One example of microplastic would be the microbeads found in face wash, toothpaste, and other daily hygiene products. Microbeads can potentially harm Great Lakes fish, such as yellow perch, who are unable to distinguish between food and microbeads. To combat the issue, President Obama signed the Microbead-Free Waters Act of 2015 — a federal ban on cosmetic microbeads that went into effect in 2017.
But one of the biggest problems with finding out how much plastic is in the Great Lakes is determining what constitutes a microplastic. The standard definition based on research is that a microplastic is any plastic debris less than five millimeters long. In the Great Lakes, which consists of 21% of the available surface fresh water on Earth, there is an estimated of estimated estimated 1.2 million particles/km² of plastic, consisting of both micro and macroplastic in surface water and shorelines. To give you an idea of how much plastic that is, it is a higher maximum count than in the North Pacific “Garbage Patch.”
On average, an estimated 22 million pounds of plastic pollute the Great Lakes annually, which makes an immediate climate conmillcern for researchers and citizens alike. Eight Great Lakes states (Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania, and Wisconsin) and Canada have been working to understand the microplastic problem, how much there is, and how to remove and slow down the pace of microplastics in our water.
The biggest concern is the Great Lakes ecosystem, both environmentally and economically, and the health of citizens. As microplastics continue to increase, there is a concern that fish and other species will continue to feed on the microplastics instead of the plankton and other small species that make up the Great Lakes bottom of the food chain. Since microplastics are so tiny, fish cannot discern them from their usual food source — zooplankton and other invertebrates. A study back in 2017 by Loyola University Chicago biologists shows that 85 percent of a sample of 74 fish from the Muskegon and St. Joseph Rivers in Michigan and the Milwaukee River in Wisconsin, that all flow into the Great Lakes, had microplastics in their digestive tract, with an average of 13 particles per fish.
Research has demonstrated numerous factors — including the plastics’ size, shape, and chemical makeup — can have harmful effects on wildlife that aren’t considered in toxicology testing. In particular, research by the University of Toronto shows microplastics in the Great Lakes are soaking up additional contaminants in the water, leading to more deformities in wildlife than when exposed to clean pre-consumer microplastics.
The effects of microplastics on wildlife inevitably translate to potential health risks for humans, especially in drinking water. A 2018 study found microplastic fibers in 159 tap water samples worldwide, including 12 brands of beer brewed with Great Lakes source waters and 12 commercial sea salt brands. That study included 33 samples from the United States with an overall average of more than nine plastic particles per sample.
Currently, the research is small on the potential impacts of ingesting microplastics by humans, but there is enough concern that governments are starting to take action. Last year, the California State Water Resources Control Board announced that they would become the world’s first regulatory authority to create standard methods for quantifying microplastic concentrations in drinking water, with the goal of monitoring water over the next four years.
According to the World Health Organization, with limited data available, health risks from chemicals and biofilms associated with microplastics in drinking water pose a low concern for human health. Microplastics enter drinking water sources in many ways, including from:
- surface run-off
- wastewater effluent
- combined sewer overflows
- industrial effluent
- degraded plastic waste and atmospheric deposition
The World Health Organization suggests that researchers should focus on targeted, well-designed, and quality-controlled investigative studies to understand the following:
- occurrence of microplastics in drinking water throughout the supply chain
- the source of microplastic pollution
- the uptake, fate, and health of microplastics under relevant exposure scenarios.
How do we remove plastics from the Great Lakes?
Even with little comprehensive research on the impact of microplastics in the Great Lakes, there are numerous ways to remove them from our water sources. Currently, removal rates of 90 percent or higher from wastewater treatment still leave a lot of microplastics in the Great Lakes. Some researchers estimate that 10,000 metric tons of plastic enter the Great Lakes each year. The cost of removing plastic from the lakes and their shorelines is estimated to be upwards of $400 million annually.
Currently, there are many programs focused on removing plastics from the Great Lakes, including the Environmental Protection Agency’s Trash Free Waters Program Operation Clean Sweep and the Responsible Care Program, and the National Oceanic Atmospheric Agency’s Marine Debris Program.
Two concepts that government, businesses, and environmental groups focus on to change the way we think about plastic and stem the tide involve Extended Producer Responsibility programs and the Circular Economy.
Extended Producer Responsibility (EPR) is an environmental policy approach in which the producer’s responsibility for a product extends beyond the manufacturing stage to the management of the products at their end-of-life stage. One example of an EPR law is Michigan’s 10-cent bottle deposit program. The program is considered a bonafide success in Michigan, where the recycling rate is a paltry 18 percent, but residents consistently return more than 90 percent of their bottles.
According to the World Economic Forum, many advocates are pushing a Circular Economy concept, which promotes the elimination of waste and the continued safe use of natural resources. Last spring, the Council of the Great Lakes Region (CLGR) launched Circular Great Lakes. This initiative will partner with chemical manufacturers, packaging producers, and other industries in the plastics supply chain to develop ways to boost plastic recycling and reduce pollution. The goal is to “close the loop” on the plastic production process with systemic overhauls in waste materials management.
Another method of removing plastic from the Great Lakes is to use resources already found in the Great Lakes — specifically algae. Researchers have recently found that one specific type of algae — Cladophora — could catch up to one trillion pieces of microplastic in the Great Lakes. Cladophora, which has expanded its range in the Great Lakes thanks to invasive mussel species, readily tangles up with plastic microfibers through adsorption. The next step is finding how we can use algae to remove microplastics from entering the Great Lakes food supply chain.
Microplastics in the Great Lakes aren’t going away anytime soon. The problem is extensive and will only worsen if we can’t work together to change our approach from how we consume plastic to how we discard and remove plastic from our environment.