Microplastics Awareness Week in Michigan, plastics in lakes, and the PFAS-induced ‘one mallard a month’ rule
This is the first time we’ve seen a microplastic awareness week so we are very impressed with our friends up North!
https://www.michigan.gov/egle/newsroom/press-releases/2025/10/15/microplastics-awareness-week
Since one of the main goals of this Week is to learn, act, and help protect the Great Lakes from tiny plastic pollution, let’s look at some of the recent studies out there regarding microplastics in lakes.
Scientists in Canada studied microplastics levels in remote Newfoundland freshwater lakes. [1] Polyvinyl chloride and polyurethane were the most commonly identified polymers, and they were also found in atmospheric samples collected during a hurricane that made landfall in Newfoundland in 2021. Given that lakes were located in sparsely populated areas and were either endorheic or had minimal inflow and outflow, local sources of MPs are negligible. Therefore, the observed MPs likely originate from atmospheric transport, delivered via rain, snow, or wind from distant sources. Once deposited, the lakes' closed-basin hydrology promotes particle retention, allowing MPs to accumulate in sediments over time.
So they concluded that most of the microplastics came down from the atmosphere. In the US, researchers looked at microplastic levels in lakes in the Adirondacks in New York State. [2] In their initial study in 2023, levels were relatively high, and were attributed to atmospheric/airborne deposition. But they later checked a similar lake that was inaccessible to hikers, and found that microplastic levels were drastically lower. Thus, they attributed the microplastic accumulation to humans - shedding from shoes and outdoor apparel.
Personally, I find it hard to believe that shoes and jackets can release enough microplastics to move the needle that much. My guess is that other human behaviors such as littering with plastic bottles, leaving behind plastic trash bags, etc. also contributed.
But of course it’s not just plastics that are accumulating in our lakes. Forever chemicals, or PFAS, are there as well. The forever chemical contamination in lakes in Green Bay, Wisconsin has spread throughout the eco-system, and now officials have released recommendations on how many ducks can be consumed safely.
Ryan AC, Maselli V, Kelly NE, Walker TR, Merschrod S EF: Atmospheric deposition drives microplastic contamination in remote lakes of Newfoundland, Canada. Science of The Total Environment 2025; 1003: 180762.
https://adkh2h.org/wp-content/uploads/Return-to-Lake-Tear-Expedition-Report-September-2025.pdf