By Dave Long
Plastic bottles, bags, straws, and packaging are often the focus for reducing plastics in Lake Michigan and the Great Lakes. But there’s a smaller, more ubiquitous type of plastic pollution, called microfibers—fibers less than 5 millimeters in length—that may pose a bigger threat and may be harder to solve. Many people are surprised to learn that one major source of microfibers is our laundry.
Synthetic microfibers which are released from plastic-based synthetic fabrics used in clothing, furniture, carpets, cigarette butts and other textiles are a subset of microplastic pollution entering the Great Lakes. Synthetic fabrics include polyester, nylon, and acrylics as well as blends of synthetic and natural fibers. When we wash textiles made from synthetic fabrics in the washing machine, tiny threads break and are released, exiting our homes with wash water where they travel to the wastewater treatment plants or to private septic systems. They are too small to be filtered out, remain in wastewater effluents, and are released to local watersheds, streams, rivers, and lakes.
To quantify the problem, Patagonia Outdoors, based in Ventura, Calif., worked with researchers at the University of California, Santa Barbara, in 2014 to explore the extent of microfiber pollution. That research, which culminated in a study published in the journal Environmental Science & Technology in 2016, examined microfiber shedding from four synthetic fleece Patagonia jackets and one from another brand.
The scientists found that when the garments were washed, an average of 1.17 grams of microfibers were released. The study also found that the amount of shedding was influenced by the type of washing machine used: Top-load machines saw seven times as many microfibers released compared to front-load washing machines. This was because front-load washing machines tend to use less water and the tumbling motions are less rigorous.
Washing machines are not the only source of microfibers. Synthetic fabrics shed microfibers all the time. Much of the dust in your home consists of microfibers created by walking on the carpet and sitting on your furniture. Activities such as cleaning carpets and furniture accelerate the shedding of microfibers. No one knows exactly how many or how all the microfibers get into the water. We do know major inputs to the Great Lakes are wastewater treatment plants, streams, rivers, runoff, and the air. A study conducted by the University of Toronto estimated 23 to 36 trillion microfibers may be released into Lake Ontario watersheds each year from washing machines alone.
It has been estimated that even more microfibers enter Lake Michigan because of the significant population centers of Chicago, Milwaukee, Grand Rapids, and Traverse City, and inputs from major rivers that feed the lake. It is not surprising that microfibers are impacting the health of the food chain in Lake Michigan and other Great Lakes. Microfibers are being found in zooplankton at the bottom of the food chain, and in fish that we are consuming.
Some of the impacts on the food chain have been identified, while other impacts can only be hypothesized. Zooplankton have been observed with microfibers blocking their intestines, which can be fatal. Mussels are filtering microfibers from the water. When these are consumed by predators, the microfibers move up the food chain. Fish stomachs have been found to be full of microfibers and microplastics. As humans we have been consuming microfibers and microplastic from sports fish from the Great Lakes, from beer made with Great Lakes water, and from tap water. Microfibers were found in each of the 12 mainly Pilsner-style beers tested from all five Great Lakes. The number of particles per liter ranged from 0-14.3 and averaged 4.05.
We all need to be concerned about the long-term impact of microfibers in the Great Lakes. Will the microfibers disrupt the food chain by killing zooplankton at the bottom of the food chain? Or will microfibers and microplastics adsorb persistent organic pollutants (POPs) and pass the toxins up the food chain to the fish we eat from the Great Lakes? We do not know the answers to these and many other questions on the impact of microfibers and microplastics. More research is needed to answer these questions.
The big question is what can we do to stop or reduce the number of microfibers entering the Great Lakes. Steps we as consumers can take to reduce the number of microfibers going into our aquatic environment include the following:
- Choose natural fibers when you can: Polyester, rayon, nylon and acrylic shed plastic fibers that are not biodegradable.
- Major clothing manufacturers like Patagonia recommend washing clothes only when needed. A study suggests most Americans wash clothes too frequently which adds to the shedding of microfibers.
- Use a front-loading washing machine: A study found that clothes shed 7 times more fibers in top-load washers compared to front loaders.
- Wash at low temperatures: Hot water can cause clothes to break down more quickly than cold or warm water.
- Use liquid detergents: Powdered detergents can be abrasive to clothes which can mechanically break fibers causing more shedding of microfibers.
- Wash heavy and light clothes separately: Mixing heavy and light clothing in the washer leads to more abrasion of the lighter clothing increasing the shedding of microfibers.
- Choose shorter wash cycle: Reducing the wash time reduces the amount of abrasion, which reduces microfiber shedding.
- Use one of the new microfiber filters: Use a GuppyFriend washing bag, which keeps microfibers inside the washing bag.
Small steps can help reduce the release of microfibers into the Great Lakes and Lake Michigan, but we are not going to stop them or eliminate them completely. We are not going to remove the trillions of fibers already in the Great Lakes. The challenge is to develop technology or filtering systems for wastewater treatment plants to remove microfibers from the treated water.
David Long is the founder of Environmental Sustainability Solutions, LLC (ESS) that provides consulting services for environmental, sustainability.