Unveiling microfiber emissions: A comprehensive analysis of household washing activities and mitigation measures

The shedding of microfibers from synthetic textiles during laundry significantly contributes to microplastic pollution in various environments. Despite growing awareness, the contribution of microfiber emissions from actual household washing machines and the potential influences of washing activities on their release remain inadequately understood. This study aims to quantify and characterize microfibers generated from different washing programs in actual household washing activities. It proposes optimal conditions for washing machine activities to effectively mitigate the environmental consequences of microfiber contamination using Response Surface Methodology (RSM). The results indicated that types of washing machines, speed of configuration and cycle duration significantly impact on microfiber release quantities. The estimated microfiber releases for the daily, quick, and delicate programs from the front-loading machine were 62.82 ± 6.29 mg/kg, 48.56 ± 15.85 mg/kg, and 12.73 ± 3.04 mg/kg, while the top-loading machine exhibited microfiber release levels of approximately 69.26 ± 3.44 mg/kg, 38.35 ± 5.54 mg/kg and 7.50 ± 2.51 mg/kg, as washing load of 4.21 kg, respectively. Polyester was identified as the predominant polymer, with an average fiber length of 1915 μm. The dominant colors of the fragments are white, dark blue, and red, which are related to the original household textiles test. The optimal conditions for reducing microfiber emissions include using a rotational speed of 1450 rpm and a cycle duration of 1.7 hours, alongside selecting appropriate washing programs with optimal durations to minimize releases during household laundry.