by the Microplastics subcommittee of the Waters and Wetlands Stewards
How guilty should we feel about wearing and washing our fleece? There is no doubt that microplastics from clothing are a major source of plastics in our waters. According to a recent article from the International Joint Commission (IJC) newsletter, “Plastic fibers, such as those found in synthetic clothing materials, are the predominant type of plastic found in Lake Superior …”. In November, 2020, Sierra Magazine reported: “Of the estimated 1.5 million tons of primary microplastics contaminating oceans each year, about 35 percent originate in synthetic clothes. Laundry is one of the main culprits.”
Microplastics are pieces of plastic smaller than 5.0 mm (about 0.2 inches). Primary microplastics are those created at the factory in small sizes such as microbeads or fibers for a fabric. Secondary microplastics are those created when larger plastic pieces break down into small pieces through physical action (tire tread wear, pounding of waves, etc.), biological degradation, or degradation from sunlight.
So, what goes into the water when you wear and then wash your fleece? A small team from the Sierra Club North Star Chapter’s Waters and Wetlands Stewards decided to test this. We proposed a “kitchen table” experiment in which we washed one fleece garment, extracted the filtered material from the wash water, and then examined it photographically.
Methods:
The Microplastics Team used a Filtrol filter installed on a washing machine, which is designed to remove microplastics from laundry wastewater.
To clean out the laundry system, we ran an empty load through the washer and the filter. We then cleaned out the Filtrol filter and ran a wash with just one fleece garment (see pictures), a men’s jacket.
The material that was captured in the filter was collected and passed to another team member for photographic analysis. We did not have a microscope, but we did have photographic equipment for extreme close-up (macro) photography. This consisted of a lens attached to a camera at the end of a long bellows. The farther the lens is from the camera body, the closer the lens can be to your subject (the fibers) and still be in focus. This provides greater magnification of the material you are examining. The camera was mounted on a copy stand for lighting and to keep the setup from shaking (see picture).
We took photos of the fibrous material recovered from washing one fleece jacket. (The red ruler lines in the photos are millimeters.)
Results:
The material extracted by the filter was very fibrous. You can see the mat of fibers in the photo. The mat is about 23 mm long (0.9 inches). There are a few unidentified particles in the mat, as well. Our best estimate of the volume is ¼ teaspoon (1.2 milliliters [ml]).
Teasing the material apart allows the individual fibers to be clearly seen. About ⅔ of the fibers were colored, but others were very clear. The close-up pictures below show the fibers teased out of the filtered material (red lines at the top of the photos are millimeters). These pictures have a long dimension of 4.3 mm (about ⅙ of an inch).
Discussion:
The filter on this washing machine was designed to remove microplastics. Normally, most lint traps and sewer system waste treatment plants would only be able to remove a small amount of this material. The rest would go into the rivers, streams, or lakes to which the system discharges.
Washing a fleece garment produces a lot of thin fibers. Because the label on the fleece garment reads "100% polyester," and since most fleece is made from a type of polyester called polyethylene terephthalate (PET), we assume that the fibers we collected fall into this category. In a real environmental analysis from a stream or a lake, it would be quite challenging to both measure and identify the fibers and particles.
When wearing a fleece garment, the fibers rub against each other and other substances (trees, rain gear, etc.). This breaks up some of the fibers and frees them from the fleece matrix. These fibers then end up in laundry waste water, which may explain why there are reports of clothing based microplastics in the soil at campsites in the BWCA.
Conclusions:
Microplastics are being found in waters and soils all over the world. They are also being found in animals and humans (placenta, baby poop). A few things are clear:
- We need to develop standard methods to measure the amounts and types of microplastics in these environments so that results of different studies can be easily compared. It would also help us determine what amounts are hazardous to animals and humans.
- We are at the beginning stages of investigating the health and biotic impacts of these tiny particles. There are many possible ways that plastics could affect humans or the environment, and we need investigations into those impacts.
We already know that microplastics produced by clothing are a significant contributor to microplastics in the environment. Even one garment washed one time produced a clump of fibers. Multiplied millions of times, this is a serious contamination problem. As we were writing this blog, we found that this study had been performed in a much more rigorous way. The report titled “Microfiber masses Recovered from Conventional Machine Washing of New or Aged Garments” captured the residue from washing new and used polyester apparel. They found that, on average, synthetic fleece jackets release 1.7 grams of microfibers each wash, or as many as 250,000 synthetic fibers and that older jackets shed almost twice as many fibers as new jackets.
We did not have a scale to measure such a small mass, but if we assume that the fibers were all polyester, and the published density for polyester is 1.38 grams per milliliter (ml), we can make a very rough calculation of the mass of our filtered material. Our ¼ teaspoon is about 1.2 ml which would indicate a mass of 1.65 grams, or very close to the average obtained in the washing machine study cited above.
That article concluded with:
“When published wastewater treatment plant influent characterization and microfiber removal studies are considered, washing synthetic jackets or sweaters as per this study would account for most microfibers entering the environment.”
Therefore, we need to look for ways to contain the proliferation of microplastics. This could involve:
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production of the fabrics to better seal in the fibers and keep them from being released
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not using plastics in clothing
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promoting laundry filters
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requiring washing machines to be outfitted with microplastics filters
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developing ways to capture/ filter out micro-plastics in waste treatment systems
Another solution, perhaps not too realistic for many people, is to use natural fibers.
What can you do now? Check out installing a filter on your laundry or investigate the Guppyfriend for washing your fleece.