By Jerri-Lynn Scofield, a former securities attorney and derivatives trader.She is currently writing a book about textile artisans.

Microfibrils—fragments of microplastics less than 5 millimeters in length—are now almost ubiquitous, found in pristine environments such as the Arctic, as well as in the human placenta.

As the Guardian reported on Tumble dryers were found to be a major source of microfiber air pollution.:

…in 2021, scientists Microplastics found to cause damage to human cells in lab. These tiny fibers are also Linked to gut inflammation and other gut problems.

A study published this week, Microfibers released into the air by home tumble dryers, found that a single household clothes dryer can release as many as 120 million such particles into the air each year, making microfibers a major source of this type of air pollution (see full study here.)

The research was conducted by a team led by Professor Liang Jianguo, Director of the State Key Laboratory of Marine Pollution (SKLMP) at City University of Hong Kong and Head of the Department of Chemistry. According to the abstract:

This study quantified the amount of two of the most common textile fibers emitted into ambient air from domestic ventilated tumble dryers. The results showed that this type of desiccant was a potential source of microfiber air pollution, releasing 433,128–561,810 microfibers within 15 minutes of use. Microfibers can be produced from polyester and cotton textiles. The abundance of polyester microfibers produced was proportional to the quality of clothes loaded into the dryer, but this relationship was not apparent for cotton textiles. Based on the results presented here and other relevant data, it is estimated that the average Canadian household could release 9 × 10⁷ to 12 × 10⁷ Microfiber from a single dryer. To minimize the release of these microfibers into the air, an appropriate engineered filtration system should be developed and employed as an effective control measure for individual household dryers.

Both organic matter (such as cotton) and inorganic matter (polyester) shed microfibers as laundry dries. Natural fibers are digested and broken down relatively quickly. Inorganic fibers are a bigger problem. According to research:

Cotton microfibers released into the environment can be ingested by organisms, but they are not as durable as polyester microfibers. For the same drying time, cotton textiles produced a more stable amount of microfibers after drying (165 ± 27), regardless of the quality of the textile in the dryer. In contrast, polyester textiles produced more microfibers than cotton textiles, according to the current results. Microfibers produced from polyester textiles are of particular interest because their bioaccumulation potential increases with decreasing size. Microfibers may be ingested and transferred into food webs by organisms ranging from zooplankton to fish and birds. [Jerri-Lynn here: my emphasis; study p. D, citations omitted.]

Prof Leung told the Guardian that filtering out such pollutants is a relatively simple job:

“Once we knew the source, we could start using simple methods to control it,” said Liang, lead author of the study. The study was published in the journal Environmental Science and Technology Letters.

Leung’s team designed filtration systems to prevent microfibers from spreading in washing machines, and is currently working on a similar system for dryers.

The challenge arises when dealing with the microfibers collected by the filter: to the Guardian:

“These [filter systems] Effectively removes most of the microfibers from clothing,” he said. However, it is unclear where these microplastics end up going after the filter is cleaned.
“If people just put these [fibres] In the bin, some of the fibers will be released back into the air,” he said. “We recommend collecting the particles in a bag. “

The question is, of course: where did that bag go? Because if you simply throw it in a landfill, these microfibers enter the ecosystem.

Filters are not a complete solution by themselves. Instead, Liang noted:

Even if installing these filters is “possible, as Leung puts it, microfibers will still be ubiquitous until the apparel industry uses greener fabrics.

To be sure, the study shows that cotton appears to outperform polyester when comparing the drum drying of organic and inorganic fibers. However, as I’ve written before, simply shifting production from inorganic fibers to cotton creates a host of environmental concerns. The most popular cotton variety currently commercially is the well-known Thirsty Plant, and a lot of pesticides are also used in most cotton production. While organic cotton production is free from pesticides, the problem of thirst remains.The restoration of traditional Indian cotton varieties is expected to address these problems, but at present, such initiatives are so small that they alone cannot meet world cotton demand in the short term (see Growing Cotton: A Small Sustainable Solution to the World’s Plastic Problem.)

Perhaps another possible short-term solution could be to dry the clothes — doing so would reduce the fossil fuel needed to run the dryer. During the mild New Jersey summers of my youth, my mom used a clothesline. However, with temperatures hovering below freezing in much of the Northeast today, dry clothes will freeze before they dry. Also, while Leung et al.’s study only dealt with tumble drying, I believe his team also found that washing machines also produce microfibers, so even eliminating the dryer altogether wouldn’t solve the problem.

The study by Leung et al. showed that a typical household clothes dryer produces large amounts of microfibers. Alas, sorting out what should be done to properly collect and dispose of these fibers is no simple task.