Clothes dryers pollute the environment with microfibers

Drying clothes too often or improperly can damage fabrics. However, scientists point to another, more serious issue. Each drying cycle releases up to 138 mg of microfibers into the environment, many of which come from synthetic materials. Can equipping dryers with better filters solve this problem?

Study on household dryers

It has been estimated that household clothes dryers in the U.S. emit about 3.5 tons of microfibers annually (for comparison: that’s 30 times the weight of the Statue of Liberty). Researchers from the Desert Research Institute (DRI) in Nevada decided to look into this issue more closely. Their study, published in Environmental Toxicology and Chemistry in September 2025, was conducted in collaboration with the non-profit organization Keep Tahoe Blue.

Volunteers participating in the experiment installed special mechanisms in their dryers to capture pollutants. They also recorded how often they used the dryers and the types of fabrics placed inside the drum.

After analyzing the filter contents, researchers found that most microfibers came from cotton and other cellulose-based fabrics. The next most common source was polyester. It is precisely these synthetic fibers that cause the greatest concern. Detailed results show that the emitted particles include polyester, polyamide, polyurethane, and polypropylene.

Are dryers with microfiber-catching filters an effective solution?

In 2023, a team of British scientists led by A.M. Cummins compared the effectiveness of filters in two types of dryers: condenser dryers (which condense water vapor and drain it into the sewer system) and vented dryers (which release warm, moist air outside). The study was conducted under real-life conditions, asking participants to dry clothing using specific programs. The results showed that condenser dryers emitted more microfibers: on average 341.5 ± 126.0 ppm (mg per kg of clothing), compared with 256.0 ± 74.2 ppm for vented dryers.

These values do not represent the total amount of pollutants reaching the air or wastewater. The actual emission was much lower thanks to the filters installed in the dryers. However, these filters are not fully effective. Filters in condenser dryers proved more efficient, capturing nearly 92% of microfibers, while those in vented dryers captured about 86%. On average, 33.3 ppm of microfibers were released into the air during each drying cycle.

The study’s authors emphasize the need to design filters with smaller pores to better trap microfibers. They also highlight the important role of dryer users in reducing pollution emissions. Even the most efficient filters are ineffective if cleaned by rinsing with water, since this sends the fibers directly into the sewage system. Scientists recommend disposing of lint collected on filters in household waste instead.

This issue was also highlighted by another research team led by Prof. Kenneth Leung from Hong Kong. As part of their experiment, they used a 3D printer to create a filter that effectively captures microfibers. However, they stress that the collected particles should be disposed of in the trash – only after sealing them in a small bag to prevent their release into the environment.

Everyday choices matter

Proper habits were also emphasized in a study published in June this year in Case Studies in Chemical and Environmental Engineering. In this experiment, participants did their laundry under household conditions using various washing machines and programs. The results showed that the smallest amounts of pollution were released when shorter and gentler programs were used. The optimal parameters were a duration of about 1 hour and 40 minutes and a spin speed of 1450 revolutions per minute.

The authors of the Tahoe Lake experiment also referred to the importance of behavioral change and simple solutions:
The study shows how small changes – such as installing more efficient pollution filters – can reduce microfiber emissions and help protect the natural environment and ourselves, said Marilee Movius, manager at Keep Tahoe Blue.

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Sources:

Monica M Arienzo, Meghan Collins, Emily Justice Frey, Marilee Movius, Laura Patten, Angelique DePauw, Rachel Kozloski, A participatory science approach to quantify microfiber emissions from clothes dryers, Environmental Toxicology and Chemistry, 2025;, vgaf222, https://doi.org/10.1093/etojnl/vgaf222

Cummins AM, Malekpour AK, Smith AJ, Lonsdale S, Dean JR, Lant NJ (2023) Impact of vented and condenser tumble dryers on waterborne and airborne microfiber pollution. PLoS ONE 18(5): e0285548. https://doi.org/10.1371/journal.pone.0285548

Rawintra Eamrat, Tatchai Pussayanavin, Somporn Tanatvanit, Yuttana Niyompong, Kamonrat Kwamman, Suphatchai Rujakom, Achara Taweesan, Unveiling microfiber emissions: A comprehensive analysis of household washing activities and mitigation measures, Case Studies in Chemical and Environmental Engineering, Volume 11, 2025, 101070,, ISSN 2666-0164, https://doi.org/10.1016/j.cscee.2024.101070