Plastic litter in life cycle assessment: advances of the marine impacts in life cycle assessment international taskforce and application to case studies

Even though marine litter, especially plastic, is viewed as an important threat to biodiversity, life cycle assessment (LCA) was late to implement any indicators allowing the consideration of this important hazard. Without these emissions included, LCA is not adequately supporting decision making with respect to plastic use and potential alternatives, and what seems like environmental solutions to the plastic problem may in fact generate more impacts on the environment. After the publication of a first framework detailing the assessment of marine plastic litter in life cycle impact assessment, the Marine Impacts in Life Cycle Assessment (MarILCA) working group has made concrete advancements in various stages of the impact modelling. Characterization factors, translating emissions flows into potential environmental impacts, were proposed in 2023 and now updated, to characterize the ecosystem damages caused by physical effects of microplastic emissions of 16 polymers, 5 sizes and 3 shapes, and applied to different case studies. Pathways associated to human health impacts from microplastics emissions are being quantified and while results are available for some polymers, challenges remain for others. This research proposes an overview of the advancements made on the quantification of the different building blocks of the impact pathways leading to damages on biodiversity and human health associated with plastic emissions in the environment, the challenges that remain, and how the results can affect decision making of plastic-based products and their alternatives when included in life cycle assessments of diverse applications including packaging, textiles, fisheries and agricultural uses.

Mots clés

• LCA
• life cycle impact assessment
• characterization factors
• MarILCA
• microplastic impacts