Occurrence of tire and road wear particles in urban and peri-urban snowbanks, and their potential environmental implications

in snow and meltwater, respectively. Comparing the levels of tire and PMB particles to the total mass of particles, showed that tire and PMB-particles combined only contribute to 5.7% (meltwater) and 5.2% (mass load) of the total mass concentration of particles. The large variation between sites in the study was investigated using redundancy analysis of the possible explanatory variables. Contradictory to previous road studies, speed limit was found to be one of the most important variables explaining the variation in mass concentrations, and not Annual Average Daily Traffic. All identified variables explained 69% and 66%, for meltwater and mass load concentrations, respectively. The results show that roadside snow contain total suspended solids in concentrations far exceeding release limits of tunnel and road runoff, as well as tire particles in concentrations comparable to levels previously reported to cause toxicity effects in organisms. These findings strongly indicate that roadside snow should be treated before release into the environment.