Marine microplastics pollution from synthetic clothes: quantitative analysis and mitigation measures

The environmental impact of plastic pollution on marine ecosystems has become an urgent problem in the last years. Marine waste consists of 60-80% of plastics and most of the debris is less than 5 mm in size. Such fragments are defined microplastics and are particularly crucial for the marine environment. They remain unaltered and, ingested by aquatic fauna, can eventually enter in the trophic chain inducing serious damages to marine fauna and human population. Recently, an unexpected source of microplastics has been discovered in washing processes of synthetic clothes like polyester, polyamide, polyacrylic and polypropylene. Due to the lack of quantitative information on this topic, this work aims to assess the role of domestic and industrial washing processes of synthetic garments on the release of microfibres. For this purpose, lab simulations of domestic and industrial washings were carried out on standard synthetic fabrics, changing washing conditions (such as temperature, time, etc.) and using different types of detergents (i.e. liquid, powder, etc.). The washing liquor was filtered and the filters were analysed by scanning electron microscopy (SEM), in order to identify and quantify micro and nanofibers detached from synthetic textiles. The obtained results allowed the identification of the parameters that mostly influence the release of microfibers and the washing conditions that are less aggressive on the fabrics. Moreover, in order to mitigate the environmental impact of the microplastics released during textile washing processes new textile finishing treatments were studied. Several textile auxiliaries were selected and applied by padding at laboratory scale, optimizing the process parameters necessary to obtain homogeneous and reproducible films on the surface of the fabrics. The effectiveness of the finishing treatments was tested through morphological and washing resistance analyses.