Stock and vertical distribution of microplastics and tire and road wear particles into the soils of a high-traffic roadside biofiltration swale.

Urban highways are a central infrastructure in megacities and represent diverse sources of microplastic pollution. Understanding the relative contribution of these microplastic sources, including the abrasion of macrolitter and the generation of tire and road wear particles (TRWP) is necessary to better assess the sources and fate of microplastics in terrestrial environments. This study focuses on microplastic (MP) and TRWP infiltration in the soil of a biofiltration swale alongside a high-traffic highway in the north of Paris, France.