Parry Sound study shows washing machine filters prevent microfibers from polluting Georgian Bay

The results are in – a demonstrated solution

Parry Sound Study

Most people wouldn't just throw plastics and other waste into the water knowingly. Unfortunately, we do so when we wash our clothes. In a washing machine cycle, our clothes shed up to hundreds of thousands of microfibers that go down the drain to wastewater treatment plants (WWTP), where many are caught, but billions get through to water bodies like Georgian Bay daily. The shedded fibers from our clothes and the chemicals they bring with them or attract from other pollutants in the surronding environment - do not belong in the water, where they are continously being dumped. Studies have shown this pollution is being found in the guts of many aquatic species and that it can cause them serious harm. It can only keep getting worse unless action is taken. We have to act.

Filters on washing machines in a laboratory setting were found to capture more than 85% of fibers before they go down the drain. But they need mass adoption and evidence that they will work in the real world.

To address this, Georgian Bay Forever is proud to announce the publication of the research article, "Washing machine filters reduce microfiber emissions: evidence from a community-scale pilot in Parry Sound, Ontario" with its partners from the Rochman Laboratory at the University of Toronto. For this research, and as a part of to Georgian Bay Forever's Divert and Capture project, 97 filters (Model: 160 Filtrol from Wexco) were installed on Parry Sound household washing machines to demonstrate that filters implemented on a wider scale will reduce microfiber/plastic pollution emissions.

November 23rd 2021 Media release about the study (PDF Download)


We partnered with Lisa Erdle, Dorsa Nouri Parto and Chelsea Rochman of the Rochman Laboratory at the University of Toronto to sample water from the effluent of the Parry Sound wastewater treatment plant and count microfibre/plastic pollution before installation of filters, and then after these filters were installed over about 2.5 year period.

Microfibers (synthetic or natural fibers that are created and modified for products) come off your clothes during laundering. These tiny strands of (less than 5 mm) can be as high as 700,000 per wash load depending on the amount and the materials in the wash (Napper and Thompson)1. In the research paper Capturing microfibers - marketed technologies reduce microfiber emissions from washing machines2(McIIwraith, 90,700 to 138,000 fibers are shed estimates based on washing one synthetic blanket. Some further 'downstream estimates' show some potentially very alarming emissions.

"Most of these fibers will travel with wastewater to a WWTP to be treated. Studies suggest that 83–99.9% of microplastics are captured in the sludge of a WWTP (Carr et al., 2016; Dris et al., 2015; Talvitie et al., 2017), with the remaining emitted to the aquatic environment via final effluent. If 99% of the 23 to 36 trillion microfibers are captured in the sludge, then up to 234 to 356 billion could be released directly into lakes and rivers annually based on our data and calculations. If the sludge is land applied, some of the remaining ~23–35.5 trillion could also be released into the environment."3

We needed to see if deploying filters outside of a lab and at higher-scale could make an important difference in pollution emissions to water bodies as therefore an important mitigating solution for Georgian Bay, the Great Lakes, North America, and beyond.

Scaling the solution

According to the research Capturing microfibers – marketed technologies reduce microfiber emissions from washing machines 2( McIlwraith at. al), the Lint LUV-R (a filter similar to the FIltrol 160) captured 87% of micofibers in the wash by count.

An important step - however - this technology's impact was not proven in a real-life situation, with many, many real families doing their laundry.

Georgian Bay Forever (GBF)and the Rochman Lab at the University of Toronto started putting together a plan involving many funders and partners to recruit about 100 volunteer households in Parry Sound, collect samples, and to do measurements and analysis.

Could this technology work outside the lab, and on a more mass scale?

YES. The results from the Parry Sound study showed a significant reduction in pollution.

Micofiber filter used in experiment in Georgian Bay
Read the full academically reviewed research article published in Frontiers in Marine Science as "Washing machine filters reduce microfiber emissions: evidence from a community-scale pilot in Parry Sound, Ontario". Find it here.

Key Takeaways include:

Demonstrated - Filters can catch a significant amount of microfiber/plastic pollution at source (i.e. the washing machine) before this pollution goes to wastewaster treatment plants.

  • "Lint samples from filters revealed an average weekly lint capture of 6.4 g, equivalent to 179,200 to 2,707,200 microfibers."
  • "The effluent samples collected before installing filters contained an average of 4.6 ± 1.6 microparticles per L (mean ± SD) of treated wastewater (Figure 4). This was significantly greater than the concentration of microparticles in samples collected after installing filters, which contained 1.9 ± 0.7 microfibers per L."
  • "We diverted at least 22.8 kg of lint over the course of our study, as measured by the 63% of households that provided samples. Based on the range of 28 to 423 microfibers per mg of lint, this equates to 639 million to 9.7 billion microfibers. If we extrapolate up to 97 households with washing machine filters, this would equate to roughly 1.2 to 18.2 billion microfibers over the course of our 487-day study."
  • "If we estimate for just one year, for the households in our study, we estimate we diverted 934 million to 14.1 billion microfibers from wastewater treatment plants annually. If we were to scale up to a large city like Toronto (1,179,057 households) or Los Angeles (3,316,795 households), and assume all households had washing machine filters, then the annual microfiber capture could be in the range of 12 to 166 trillion microfibers for Toronto or 30 to 468 trillion for the county of Los Angeles."

Demonstrated - Filters led to a decline in pollution in the effluent (what goes out to water bodies after treatment).

  • "In addition to household capture of microfibers in laundry lint, we observed a significant decline in the number of microfibers in final effluent at the municipal WWTP. This directly equates to less microfibers entering Lake Huron via treated effluent. After installing washing machine filters, we observed a reduction in microfibers in final effluent by an average of 41%. This significant difference in microfiber count pre- and post- filter deployment suggests that adding filters to washing machines reduces microfiber emissions to water bodies via treated wastewater."
  • "We are, however, surprised at such a large decrease in microfibers, especially since filters were only installed in 10% of homes. A possible explanation for a more substantial decrease than what we expected could be related to behavioural change. Due to local recruiting efforts and awareness campaigns [as part of the Georgian Bay Forever Divert and Capture program] , microfiber awareness may have increased in this community, which could have indirect effects. For example, if awareness campaigns led to changes in washing habits (i.e., washing less, washing with cold cycles, using a washing bag), this could contribute to further microfiber emission reductions. To test whether applying filters in a community can lead to indirect reductions in microfiber emissions from modified laundering practices, future work could focus on whether community-wide pilots impact behaviour."

Microfiber pollution from washing your clothes is synthetic AND is also plant-based (like cotton for example). Both are cause for concern.

  • "We found both natural and synthetic microfibers in wastewater samples, although natural anthropogenic microfibers were by far the most common material type. Even though research suggests that some types of fibers can degrade in the environment, others are more persistent (Bonanomi et al., 2020; Sørensen et al., 2021; Zambrano et al., 2019). In addition, there is a growing concern over synthetic and natural microfiber emissions due to additive chemicals (e.g., treatments and dyes; Lacasse and Baumann, 2004; Schellenberger et al., 2019; Xue et al., 2017), bioavailability to organisms (Athey et al., 2020; Gago et al., 2018), and toxicity (Kim et al., 2021; Mateos-Cárdenas et al., 2021)."

Front loader washing machines better than top loaders in terms of limited shed of microfibers from clothing.

  • "Previous research shows that top loader washing machines shed more microfibers than front loading washing machines (Hartline et al., 2016), and our results support this finding. We found that filters from top loader washing machines captured 1.5x more lint per week than front loading washing machines. This is equivalent to an additional 70,000 to 1,057,500 microfibers per week, assuming top loading machines captured an average of 2.5g lint per household per week more than front loading machines and lint contains 28 to 423 microfibers/mg. This suggests that front loader machines result in the shedding of less fibers, and that top loading machines should receive filters first if efforts aim to retrofit existing washing machines with filters."

Next Steps for Georgian Bay Forever

Working with you and our partners to take these results to many more people and policy makers to make filters and education about microfiber pollution top of mind, and something that everyone can act on to stop.

To understand more, please download this 2 page policy paper.

Why is the Parry Sound research important and what can you do?

The results show that filters on washing machines work to reduce microfiber/plastic pollution from getting into the water
- BUT HARDLY any households have these filters.

There are critical things you can do.

1. Write your Ontario MPP immediately saying that you support Private Member's Bill 279.
This Bill will "prohibit the sale or offering for sale of washing machines that are not equipped with a specified microplastics[microfibre] filter and to provide for corresponding penalties in case of non-compliance with the requirement." We need to make washing machines with filters widely and more easily available in the future to everyone who purchases a new washing machine.
  • Find information HERE about writing your Ontario MPP.
  • Bill 279: An Act to amend the Environmental Protection Act with respect to microplastics filters for washing machines. Status and information HERE.

2. Reduce your own microfiber/microplastic waste.
  • Consider buying a filter for your own washing machine. There are different filters on the market. The U of T Rochman lab tested 2 outside washing machine filters. The Lint Luv'r and the Wexco FIltrol 160, and found they were 87 to 89% effective at capturing filters. Both are available in Canada if you search online (if you buy outside of Canada, you will be subject to fees). Last time we looked they cost anywhere from $180 to around $220 BEFORE installment and shipping. For the Divert and Capture project, GBF installed the Filtrol 160 from Wexco into Parry Sound residences.It's also important for septics. Read why at this link.
  • Follow these tips to reduce microplastic/fiber pollution. General tips include avoiding over consumption of clothing, decrease your laundering and using cold water, and minimizing one-use plastic like bags.
    - A PDF download on tips to reducing microfiber plastics from getting into the environment. Click here.

- Check out this 10 tip video.

GBF would like to thank these funders for their support of the Parry Sound Divert and Capture Project and this research.

The ECCC EcoAction Community Funding Program, Lush Handmade Cosmetics Ltd., Patagonia Environmental Grants Fund of Tides Foundation, RBC Foundation, Charles H. Ivey Foundation, J.P. Bickell Foundation, LeVan Family Foundation, Helen McCrea Peacock Foundation, and GBF Donors.

More information on Divert and Capture - the fight to keep microplastics out of our water, and other plastic mitigation projects at. Microplastics and Microfibres Impacts

GBF wishes to acknowledge the support of these partners:
The Rochman Laboratory at the University of Toronto
The Diamond Environmental Research Group at the University of Toronto
The Town of Parry Sound
The Georgian Bay Biosphere Reserve
The Ontario Ministry of the Environment , Conservation and Parks
Fashion Takes Action
and our many community volunteers!

These partners are helping spread the word:
The University of Toronto Trash Team
The Township of The Archipelago
The Township of Georgian Bay
Georgian Bay Association
The Severn Sound Environmental Association
Blue Mountain Watershed Trust
The Great Lakes St. Lawrence Cities Initiative

Important results.
Thank you Parry Sound volunteers for showing all of us what filters can do, and being passionate about reducing microfiber and microplastic pollution.

1Napper, Imogen E. and Thompson, Richard C. ""Release of synthetic microplastic plastic fibres from domestic washing machines: Effects of fabric type and washing conditions" , Marine Pollution Bulletin ,Volume 112, Issues 1–2, 15 November 2016, Pages 39-45 retrieved from ScienceDirect at
2McIlwraith, Hayley K.; Lin, Jack; Erdle, Lisa M.; Mallos, Nicholas; Diamond, Miriam L.; Rochman, C.M " Capturing microfibers – marketed technologies reduce microfiber emissions from washing machines" , Marine Pollution Bulletin Volume 139, February 2019, Pages 40-45, retrieved from ScienceDirect at
3McIlwraith, Hayley K.; Lin, Jack; Erdle, Lisa M.; Mallos, Nicholas; Diamond, Miriam L.; Rochman, C.M" Capturing microfibers – marketed technologies reduce microfiber emissions from washing machines" , Marine Pollution Bulletin Volume 139, February 2019, Page 44, retrieved from ScienceDirect at
Lisa M. Erdle, Lisa M; Nouri Parto, Dorsa; Sweetnam, David; and Rochman, Chelsea. Washing machine filters reduce microfiber emissions: evidence from a community-scale pilot in Parry Sound, Ontario, Frontiers in Marina Science, Marine Pollution.