A persistent methodological gap

Life cycle assessment (LCA) overlooks the impacts of plastic pollution. A package discarded into the environment, a microfibre released during laundering or a tire and road wear particle emitted onto the roadway are covered by no conventional impact category. This absence distorts comparisons between materials: replacing a plastic with an alternative may look advantageous in climate or water terms while shifting the environmental burden to a compartment the method does not measure. Without a dedicated indicator, LCA can neither arbitrate these trade-offs nor inform ecodesign and public policy decisions concerning plastics.  

An international working group

MarILCA (Marine Impacts in Life Cycle Assessment) was created in 2018 with the support of the Life Cycle Initiative of the United Nations Environment Programme and the Forum for Sustainability through Life Cycle Innovation (FSLCI). The group brings together CIRAIG, the Pontificia Universidad Católica del Perú (PUCP), NTNU and UCSB, and is chaired by Anne-Marie Boulay (CIRAIG, Polytechnique Montréal) and Ian Vázquez-Rowe (PUCP), alongside Francesca Verones (NTNU).  

Three lines of research

Quantifying leakage. Estimating the plastic flows that escape waste management systems. This inventory work spans sectors as diverse as packaging, textiles, agriculture and road transport. Modelling environmental fate. Once emitted, particles fragment, degrade, settle or migrate between compartments. The multimedia models developed within MarILCA build on established LCA frameworks, such as SimpleBox4Plastics. Characterizing impacts. Plastics act through several distinct pathways: physical effects on biota through entanglement, smothering and ingestion; toxicity of leached additives; human exposure through the diet; disruption of ecosystem services such as ocean carbon sequestration. Each calls for its own impact pathway and characterization factor.  

Student research at CIRAIG

A substantial share of MarILCA research is carried out by CIRAIG students:  

• Framework of Impact Pathways on Marine Ecosystems for Life Cycle Impact Assessment — Sam Jarouche, master’s student. Review of existing procedures linking marine ecosystems to human activities, in order to identify methodological blind spots and priority research needs.

• Impacts of microplastics on ecosystem quality and the marine carbon cycle — Nadim Saadi, PhD student. Modelling the environmental fate of microplastics and cellulosic microfibres across regions and ecosystems, quantifying damage to ecosystem quality and assessing their influence on the marine carbon cycle.

• Tire and road wear particles — Louisa Ospital, PhD student. Development of a regionalized inventory model of TRWP emissions, a multimedia fate model and a dedicated characterization factor. The project benefits from a collaboration with Michelin and the Tire Industry Project.
• Characterization factors for the human health impacts of micro- and nanoplastics — Arthur Beteille, PhD student. Assessment of the toxic effects of micro- and nanoplastics and of human exposure through dietary ingestion, with a view to deriving the first characterization factors for human health.
• Impacts of microplastics on the ocean carbon cycle — Luc Dauge, master’s student. Identification of the biophysical mechanisms by which microplastics disrupt carbon sequestration fluxes, quantification of these disruptions and integration of the resulting factors into the MarILCA framework.

This work at CIRAIG is supervised by Anne-Marie Boulay.