Environmental impact of fibrous microplastics from laudering on aquatic biota

The low cost and flexibility in various applications made plastics an essential asset for the manufacturing industry. Still, the increase in annual plastic production has led to growing concerns about the dispersion of macro and microplastics in the environment. The massive use of plastics in various industrial sectors has led to a surge in plastic waste, often poorly managed, contributing, along with the unfortunate phenomenon of littering, to the rampant presence of plastics in the environment. Furthermore, macroplastics (with sizes larger than 5 mm) fragment over time into secondary microplastics (1μm – 5mm), facilitating their leakage into the environment. On the other hand, primary microplastics are directly released by the technosphere, both during manufacturing and packaging processes and during activities such as washing synthetic fabrics. These contaminants represent an emerging environmental problem due to their persistence and negative effects on health and the ecosystem. Microplastics can carry chemical additives or promote their accumulation on their surface and, at a physical level, can bioaccumulate in living organisms through internal pathways, compromising their functions and leading to death. Life cycle analysis is a tool used in the evaluation of the environmental impact of products, services, and activities, which is capable of providing useful elements for identifying sustainable practices and environmental hotspots to stakeholders and legislators for the implementation of targeted standards and policies. Currently, the Life Cycle Assessment (LCA) methodology does not track the dispersion of microplastics and their contribution to the environmental impacts of a product. This necessity has recently driven the development of tools to support the tracking of plastics and microplastics during the supply and production chain and their dispersion, such as the Plastic Leak Project. In this framework, models have also been developed that statically or dynamically describe the fate mechanisms of plastics in the environment, to promote efforts to include the role of microplastics in LCA. Thanks to these contributions and studies on the toxicity of plastics on marine biota, proposals have emerged in recent years to quantify the environmental impact of microplastics through old and new impact categories. The objective of this project is to contribute to the assessment of the role of microplastics in defining the environmental profile of a synthetic textile product, strictly related to their dispersion industrial or domestic washing processes. Firstly, the release of microplastics has been quantified and characterized during a simulated washing process by harmonizing the UNI EN ISO 4484-1 and ISO 4484-2 standards, evaluating the emission during the first wash, indicative of the contribution due to production processes, and during the third wash. The physical effect on marine and freshwater biota has been evaluated according to different methodologies, critically analyzing the results and differences. Furthermore, recommendations to LCA practitioners regarding intricacies and limitations of the current methodologies have been discussed to support future developments and shared methodological frameworks.