More than 30 Great Lakes scientists have called on Illinois legislators to establish a science-based standard for capturing plastic microfibers released from washing machines. By setting a standard, not a specific technology, and phasing it in over five years, a bill currently under consideration in the Illinois legislature allows washing machine manufacturers the flexibility and time to integrate this standard into new machines and products. This legislation will significantly reduce the amount of plastic microfiber pollution entering our lakes, rivers, lands, and local wastewater systems, thereby protecting our drinking water.

One existing technology is microfiber filters, which are similar to lint filters in the dryer. Microfiber filters can capture 90% of microfibers from a load of laundry.
Protecting the Great Lakes from the environmental and health risks of plastic microfiber pollution is critical. The Great Lakes provide drinking water for more than 30 million people and are home to diverse and increasingly threatened wildlife. Plastic in the environment never really goes away. Instead, it breaks down into smaller and smaller pieces, known as microplastics.
Plastic microfibers are the most prevalent form of microplastics in environmental samples and represent over 90% of microplastics ingested by marine animals. Plastic microfibers come from plastic-based textiles and clothing. More than 18 million microfibers can be released in just one load of laundry. In animals, ingestion of microfibers has been shown to reduce food consumption, reduce energy for growth, alter gene expression, and block digestive tracts. An ever-expanding body of research is identifying the human health impacts of microplastics.
Microfibers are common throughout the Great Lakes habitats and wildlife, including streams, rivers, agricultural soils, and wildlife. They flow via washing machine effluent into wastewater treatment plants, primarily resulting in the biosolids left over from treatment. These biosolids are then applied to Illinois lands as fertilizer, releasing microfibers into the environment and contaminating agricultural soils. A recent analysis showed that Illinois is among the top five states with the most abundant microplastics from biosolids.
Worse yet, microfibers are a persistent pollutant. Once in the environment, they are nearly impossible to clean up, which is why it is critical to prevent these particles from escaping into the environment in the first place.
The scientist’s letter expresses support for Illinois General Assembly bill HB1370, sponsored by Illinois State Representatives Daniel Didech and Kim du Buclet, along with companion Senate bill SB0030, sponsored by Illinois State Senator Julie A. Morrison. These bills are currently being considered during the spring session of the Illinois General Assembly.
The full text of the letter is below:
The Honorable Carol Ammons, Chair
Illinois General Assembly
House Energy and Environment Committee
RE: Support for–Microfiber Prevention and Washing Machine Filtration Legislation HB 1370
Dear Chair Carol Ammons,
We want to express our support for the microfiber filtration legislation, which will significantly reduce the amount of microfiber pollution entering lakes, rivers, lands, and local wastewater systems, preventing harm to our drinking water.
“Microfibers” are small thread-like microplastic fibers less than 5 mm. They are derived from textiles and typically contain chemical additives, including dyes and plasticizers, to give the finished product characteristics such as heat resistance, waterproofing, flexibility, and antimicrobial properties.
Microfibers are generated throughout the entire lifecycle of clothing manufacturing and cleaning. Washing clothes is a primary source of microfibers to the environment because up to 18 million microfibers can be released during a single wash[1]. In fact, the amount of microfibers released from 100,000 fleece jackets could be as high as 0.65 – 3.91 kg (1.4 – 8.6 lbs.). Microfibers from washing clothes enter wastewater treatment plants (WWTPs) – which are not engineered to capture microfibers – so a meaningful fraction makes it through to the treated effluent. For example, a team of Illinois researchers measured microplastics in raw sewage, sludge, and treated effluent at a few sites in the Chicago suburbs. A recent analysis showed that the relatively small WWTP in Bartlett, Illinois, which treats 1.9 million gallons of wastewater/day, releases approximately 9,500 microplastic particles into the DuPage River every day. Within WWTPs, most microfibers are captured in the sewage sludge (biosolids)[2]. Under current best practices in Illinois, the sewage sludge is converted to ‘biosolids’, or fertilizer, that must be land applied. Biosolids containing microfibers are thus used by our state’s farmers and homeowners and, from there, can pollute terrestrial environments, the air, and our waterways.
Countless studies have revealed that microfibers are one of the most abundant types of microplastic globally, including in Illinois and the Great Lakes region. Microfibers are common throughout the Great Lakes habitats and wildlife, including streams, rivers, agricultural soils, and wildlife. For example, a recent study examined fish collected in Chicago-area rivers over the last 100 years, stored at the Field Museum of Natural History[3]. The results showed that microplastics, including microfibers, first appeared in fish digestive tracts in the mid-1900s and have increased in abundance since then.[4] This study concluded that although microplastic pollution is a relatively recent focus of research, its presence in the environment has been a feature of industrial plastic production since it began.[5] [6] Microfibers have unique negative effects on wildlife and humans compared to other microplastics. They have a distinct shape from other microplastics and are associated with a different suite of chemicals from manufacturing and environmental exposure. Microfibers can act as a vector for the transport of toxic chemicals such as PFAS, brominated flame retardants, and harmful dyes, posing risks to wildlife, the environment, drinking water, and people. In addition, microplastics can harbor some disease-causing microorganisms as they move through WWTPs and enter our rivers. Although research on the chemical fate and toxicity from microfibers is still in its infancy, findings demonstrate that microfibers can alter feeding behavior, reproduction, and survival. A review of the health impacts of microplastics on mammals showed inflammation and oxidative stress were consistent effects of microplastic exposure across species.[7] Studies on human health implications are still emerging, but recent research has shown a link between microfibers in lung tissue and tumor formation.
Communities throughout the Great Lakes region rely on their clean and abundant water for many uses, including drinking water. Microplastics are widespread in the Great Lakes, and not all are captured during filtration and chemical treatment of drinking water. Microfibers also pollute groundwater, another common source of drinking water for many communities in our region.[8] Agricultural soils are also contaminated with microfibers, which likely originates from the use of biosolids on farm fields. A recent analysis showed the states with the greatest abundance of microplastics from biosolids are Nebraska, Minnesota, Iowa, and Illinois.[9]
Worse yet, microfibers are a persistent pollutant. Once in the environment, they are nearly impossible to clean up, which is why upstream interventions are critical in preventing these particles from escaping into the environment in the first place. Thus, it is essential to reduce the sources of microfibers now before their environmental impact further increases.
Interventions that capture microfibers before they’re released to wastewater are needed now to address microfiber pollution. The filtration systems required by HB 4269 are a solution we know to be effective from numerous laboratory studies and field investigations. A 100 μm filter, as would be required under HB 4269, can capture up to 90% of microfibers in a load of laundry. Furthermore, they can also be an effective solution at the regional scale; a community-level study of filters installed in 97 homes in Ontario, Canada, showed a significant reduction in microfibers in the wastewater system after installing filters.
Illinois has the opportunity, with Washing Machine Microfiber Filtration legislation, to lead the nation once again in addressing microplastic pollution. With effective filtration solutions available, we cannot afford to wait to address the threats of microfiber pollution from our drinking water and from flowing into our environment. As representatives of the scientific community, we suggest acting now, before environmental concentrations reach an even higher level that exacerbates harm to wildlife, drinking water, people, and the planet.
Sincerely,
Timothy Hoellein, Ph.D.
Professor
Department of Biology
Loyola University Chicago
John Kelly
Biology Department Chair, Professor
Loyola University Chicago
Reuben P. Keller, PhD
Professor, Graduate Program Director
School of Environmental Sustainability
Loyola University Chicago
Sherri Mason
Associate Research Professor and Director of Sustainability,
Penn State Behrend
Chelsea Rochman
Assistant Professor
Department of Ecology and Evolutionary Biology
Head of Operations & Science Programming and Application Lead U of T Trash Team
University of Toronto, Canada
Aaron Packman
Professor of Civil and Environmental Engineering
Northwestern University
Mike M. McMahon
Strategic Partnerships Administrator
Paula M. Trienens Institute for Sustainability and Energy
Caleb D. McMahan
Head of Zoology Collections
Collections Manager, Fishes
Field Museum of Natural History
Sarah Zhou Rosengard
Assistant Prof
School of the Art Institute of Chicago
John W Scott
Associate Research Scientist, Senior Analytical Chemist,
Illinois Sustainable Technology Center
Dr. Bill Perry
Professor of Ecology
Illinois State University
Jaclyn Wegner
Director, Conservation Action
Shedd Aquarium
Austin Happel
Research Biologist
Shedd Aquarium
Carolyn Foley
Research Coordinator
Illinois-Indiana Sea Grant
Purdue University
Tomas Höök
Department of Forestry and Natural Resources
Purdue University
Robert Stelzer Ph.D.
Professor and Graduate Coordinator
Department of Biology
University of Wisconsin, Oshkosh
Eric Strauss
Professor, Dept. Biology
University of Wisconsin, LaCrosse
Dr. Lorena Rios Mendoza
Professor, Natural Sciences Department
University of Wisconsin, Superior
Catherine Searle
Assistant Professor
Perdue University
Gary Lamberti
Professor, Department of Biology
University of Notre Dame
Jennifer Tank
Ludmilla F., Stephen J., and Robert T. Galla Professor of Biological Sciences
Director of Environmental Change Initiative (ND ECI)
University of Notre Dame
Alan D. Steinman
Allen and Helen Hunting Research Professor
Grand Valley State University
Donna Kashian
Professor, Director of Environmental Science
Wayne State University
Suchy, Amanda
Post doctoral researcher
Central Michigan University
Melissa Duhaime
Dept Ecology and Evolutionary Biology
University of Michigan
Matthew Hoffman
Professor, School of Mathematics and Statistics
Rochester Institute of Technology
Christy Tyler
Associate Professor and Director of the Graduate Program in Environmental Science
Rochester Institute of Technology
Melissa Maurer-Jones
Associate Professor, Swenson College of Science and Engineering
University of Minnesota – Duluth
Diane Orihel
Associate Professor, Queen’s National Scholar in Aquatic Ecotoxicology
School of Environmental Studies/Department of Biology
Queen’s University, Canada
Michael Rennie
Canada Research Chair in Freshwater Ecology and Fisheries
Associate Professor and Graduate Coordinator, Department of Biology
Director, Aquatic Toxicology Research Centre
Lakehead University, Canada
Rebecca Rooney
Principal Investigator, Waterloo Wetland Lab
Associate Professor, Department of Biology
University of Waterloo
Patricia Corcoran
Professor, Dept. of Earth Sciences
University of Western Ontario, Canada
Tony Walker
Professor, School for Resource and Environmental Studies
Dalhousie University, Canada
Scott Higgins
Senior Research Scientist
International Institute for Sustainable Development -Experimental Lakes Area
Michael Paterson
Senior Research Scientist
International Institute for Sustainable Development -Experimental Lakes Area
[1] Scott J, Prada A, Green L. The Transport of Emerging Contaminants (Microplastics and PFAS) in Landfill-Wastewater Treatment Systems. TR Series (Illinois Sustainable Technology Center); 80. 2023. https://www.ideals.illinois.edu/items/128768
[2] Kelly, J.J., London, M.G., McCormick, A.R., Rojas, M., Scott, J.W. and Hoellein, T.J., 2021. Wastewater treatment alters microbial colonization of microplastics. PloS one, 16(1), p.e0244443. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0244443
[3] Hoellein T, Rovegno C, Uhrin AV, Johnson E, Herring C. Microplastics in invasive freshwater mussels (Dreissena sp.): spatiotemporal variation and occurrence with chemical contaminants. Frontiers in Marine Science. 2021 Jun 29;8:690401.
[4] Lenaker PL, Baldwin AK, Corsi SR, Mason SA, Reneau PC, Scott JW. Vertical distribution of microplastics in the water column and surficial sediment from the Milwaukee River Basin to Lake Michigan. Environmental science & technology. 2019 Oct 16;53(21):12227-37.
[5] Koyuncuoğlu P, Erden G. Sampling, pre-treatment, and identification methods of microplastics in sewage sludge and their effects in agricultural soils: a review. Environmental Monitoring and Assessment. 2021 Apr;193:1-28.
[6] Hou L, McMahan CD, McNeish RE, Munno K, Rochman CM, Hoellein TJ. A fish tale: a century of museum specimens reveal increasing microplastic concentrations in freshwater fish. Ecological Applications. 2021 Jul;31(5):e02320. https://esajournals.onlinelibrary.wiley.com/doi/full/10.1002/eap.2320
[7] Coffin S, Bouwmeester H, Brander S, Damdimopoulou P, Gouin T, Hermabessiere L, Khan E, Koelmans AA, Lemieux CL, Teerds K, Wagner M. Development and application of a health-based framework for informing regulatory action in relation to exposure of microplastic particles in California drinking water. Microplastics and Nanoplastics. 2022 May 25;2(1):12.
[8] Panno SV, Kelly WR, Scott J, Zheng W, McNeish RE, Holm N, Hoellein TJ, Baranski EL. Microplastic contamination in karst groundwater systems. Groundwater. 2019 Mar;57(2):189-96.
[9] Naderi Beni N, Karimifard S, Gilley J, Messer T, Schmidt A, Bartelt-Hunt S. Higher concentrations of microplastics in runoff from biosolid-amended croplands than manure-amended croplands. Communications Earth & Environment. 2023 Feb 20;4(1):42.