Louisa Ospital

Despite their ubiquity in road traffic emissions, Tire and Road Wear Particle (TRWP) are currently omitted from Life Cycle Assessments (LCAs) of traffic-related emissions, leaving their potential environmental impacts overlooked. To address this critical gap, we developed a regionalized Life Cycle Impact Assessment framework introducing two main methodological advances: (1) a size- and shape-resolved multimedia fate assessment, adapted from SimpleBox4Plastics and tailored specifically to TRWP physical properties, coupled with a technosphere redistribution model to track mass transport from initial emissions to environmental sinks; and (2) TRWP-specific exposure and effect factors that systematically decouple particle physical effects in aquatic and terrestrial ecosystems from chemical ecotoxicity caused by additives leached and dissolved in surface waters. Combining these fate and effect factors yields operational midpoint and endpoint characterization factors for Ecosystem Quality compatible with IMPACT World+, GLAM, and ReCiPe methods. Multimedia fate modeling identifies benthic sediments as the main environmental sink (>70% of emitted mass). Although dissolved chemical leachates exhibit higher ecotoxicity than whole particles per unit mass, rapid particle sedimentation limits additive accumulation in the water column, causing particle physical effects to dominate total aquatic impacts by up to four orders of magnitude. This study provides the operational, regionalized CFs required to systematically integrate TRWPs into road-transport-related LCAs while advancing the impact assessment of complex microplastics and their chemical additives.

Highlights● Fate factors in terrestrial, freshwater and marine compartments are calculated● The marine fate integrates the TrackMPD ocean tracking model● The fate factors are region, material, size, shape, and compartment-specific