Microplastics have been found in the environment, e.g., throughout the food chain in the oceans. Fibers that are released while laundering synthetic fabrics are one major source of this pollution. Microfibers are known to be released during machine washing of clothing made from synthetic fibers, but it had been less clear how hand washing contributes. Hand washing is still common in some regions of the world.
Hongting Zhao, Foshan University, Guangdong, China, Baoshan Xing, University of Massachusetts, Amherst, USA, and colleagues have systematically investigated the microplastic fiber release from synthetic textiles caused by different methods of hand washing in comparison with machine washing. The researchers cleaned two types of fabric swatches, made from either 100 % polyester or a 95 % polyester/5 % spandex blend with different hand washing methods or a washing machine. After laundering, the washing liquid and rinsing liquid were filtered and the fibers were counted and measured.
The team found that hand washing can drastically reduce the number of fibers shed compared with using a machine. For example, the 100 % polyester fabric shed an average of 1,853 microplastic pieces during hand washing, compared with an average of 23,723 pieces when the same fabric was machine washed. By weight, machine laundering released over five times more microplastics than hand washing. In addition, the fibers released from hand washing tended to be longer.
The researchers observed that, e.g, using a washboard increased the number of fibers released by manual methods, while variations in temperature, detergent type, and wash time had no significant effects on the microplastic release during hand washing. According to the team, the work could provide guidance for “greener” laundering methods.
- Microplastic Fiber Release by Laundry: A Comparative Study of Hand-Washing and Machine-Washing,
Chunhui Wang, Weikun Chen, Hongting Zhao, Junhong Tang, Gang Li, Qian Zhou, Jingtao Sun, Baoshan Xing,
ACS EST Water 2023.