Laundering and textile parameters influence fibers release in household washings

Synthetic fibers represent one of the main forms of microplastics in marine environment and recently were related to household washings as a source. Although other types of fiber, like natural, do not rely under this classification, there is a potential for them to act as a vector of toxic substances to biota in the same way as microplastics do. Consequently all types of fiber have the potential to cause variable ecologic and socioeconomic impacts. In this scenario, the present study aimed to investigate the effects of washing parameters in the emission of fibers on textiles with different characteristics and fiber content: cotton, acrylic, polyester and polyamide. For this purpose individual garments were sequentially washed with and without detergent. Results showed that the use of a detergent reduced significantly the mass of particles emitted from synthetic garments but not from cotton, which, in relative terms, was responsible for the highest emissions. Textile characteristics such as mass availability and fiber cohesion influenced results, where shorter irregular fibers and lower tenacities dealt to higher releases. For all types of garments tested, 10 sequential cycles decreased particles' release, with peaks in three firsts washes (from 37% to 76%). Taking into account a regular washing machine filter, a considerable mass of fibers (from 40% to 75%) was not retained by this device, indicating a potential for improvement. Together, simple solutions as the use of detergents, three pre-washes and superimposed filter meshes, could diminish >53% of this type of pollution. Besides this potential reduction, globally, in one year, domestic washing machines would still contribute with around 15 thousand tonnes of cotton and synthetic fibers. A structured and sustained solution for this problem should advance in an interdisciplinary approach, fomenting responsibility from plural actors, taken in all stages of products' life cycle.