Laundry machines in Canada and the U.S can release upwards of 878 tonnes of microfibres to the aquatic environment each year following wastewater treatment, according to a new study by the Ocean Wise Plastics Lab in Vancouver.
Believed to be the most comprehensive study of its kind, researchers evaluated the shedding properties of 38 textile samples, using a custom-designed washing machine test facility and a dedicated high-resolution analytical laboratory.
The study found that while most microfibers are retained during wastewater treatment processes, municipal wastewater releases as many as 3.5 quadrillion microfibers into the freshwater and ocean environments every year in Canada and the U.S.
Researchers also found that different fabrics shed microfibers during home laundry through a wide range, and that fabric properties influenced the degree to which fibers were lost during a wash cycle. A single garment can release as many as 120-730,000 microfibers in a laundry cycle, but most textiles lost the greatest number of microfibers in the initial wash compared to subsequent ones.
“Clothing lies at the heart of this study,” the authors state. “And, while researchers are adept at identifying and characterizing problems, solutions often feel less tangible, more distant, and difficult to achieve. Our overall hope is that these findings provide a conduit to solutions at multiple levels, be these consumer decisions, green design by the apparel sector, wastewater treatment plant construction, or government leadership. In this light, we as individuals all have a chance to step up and stem the release of microfibers into the environment,” the researchers add.
Authors Katerina Vassilenko, Mathew Watkins, Stephen Chastain, Anna Posacka and Peter Ross note that the loss of fibers by textiles during home laundry may explain in part the abundance of microfibers found in the ocean.
The research suggests that approximately 60% of the 30 billion microplastics emitted annually by a secondary treatment facility in Vancouver are microfibers, with additional evidence from other studies pointing to an abundance of synthetic particles in wastewater effluent.
The new report, entitled Me, My Clothes and the Ocean: The role of textiles in microfiber pollution, was produced with the support of four apparel firms – MEC, Patagonia, REI and Arc’teryx – and Metro Vancouver and Environment and Climate Change Canada.
Polyester textile samples — dominated by mechanically-treated polyester fleeces and jerseys — shed the most (average of 161 ± 184 mg per kg of textile per wash), compared to nylon textiles with filament-type yarns and a woven construction (average of 27 ± 16 mg per kg of textile per wash). Interestingly, cotton and wool textiles also shed large amounts of microfibers (average of 165 ± 44 mg per kg of textile per wash). Textile properties such as yarn type, mechanical treatment and chemical finish likely explain differences in shedding among the materials tested, highlighting the value of additional applied research.
In 2017, the Ocean Wise Plastics Lab launched the Microfiber Partnership, “a solution-oriented research initiative that brings together researchers, the apparel industry, and government agencies concerned about the sources and impacts of microfiber pollution in the ocean.” The Phase 1 research objectives of the partnership address three topics: Home laundry as a source of microfibers in the environment; retention, fate and discharge of microfibers in a secondary wastewater treatment plant; and forensic methods for the identification of textile microfibers following weathering in air, seawater and wastewater.