Textiles can release microfibers, e.g., during washing. Microfibers released from synthetic textiles such as polyester can contribute to microplastics pollution. Microfibers can not only contaminate water, but can also be airborne. The generation of microfibers from washing machines has been studied, while less is known about their release from the vents of household tumble dryers into the air.

Kenneth M. Y. Leung, City University of Hong Kong, Kowloon, Hong Kong SAR, Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai, China, and colleagues have measured the number of common textile microfibers (polyester and cotton) discharged from a household vented tumble dryer into the air. The team separately dried different types of polyester or cotton textiles (pants, t-shirts, jackets, blankets, etc.). They used a vacuum pump connected to an air sampler to collect microfibers from the air that was released during the drying process. The released textile microfibers were collected in the sampler on glass-fiber filters and then counted under a microscope. The total number of released fibers for 1 kg of textiles was then estimated based on the counts.

The researchers found that ca. 94,000 and ca. 72,000 microfibers could be released from 1 kg of polyester and cotton textiles, respectively, within 15 min. These values are higher than those reported for fibers released during washing. A household with 219 loads of laundry annually could release 9·10⁷ to 12·10⁷ microfibers from their dryer within a year. Polyester microfibers, in particular, could accumulate in the environment, while natural cotton microfibers are not as persistent. The team points out that the release of microfibers from tumble dryers could be minimized by the installation of filtration devices in dryer vents.

• Microfibers Released into the Air from a Household Tumble Dryer,
  Danyang Tao, Kai Zhang, Shaopeng Xu, Huiju Lin, Yuan Liu, Jingliang Kang, Tszewai Yim, John P. Giesy, Kenneth M. Y. Leung,
  Environ. Sci. Technol. Lett. 2022.
  https://doi.org/10.1021/acs.estlett.1c00911