Ecotoxic potential of road-associated microplastic particles (RAMP)

Summary

Road-related microplastic particles (RAMP) is a group of particles in the microscale size range 0.1-1000 μm with plastic compounds (polymers) in them, which is present in road runoff. Tire-wear particles (TWP) are estimated as the largest single source of microplastic particles in Norway, contributing up to 5000 tons of microplastic per year of a total of 8400 tons of microplastics per year. RAMP also includes road-wear particles from polymer-modified bitumen (RWPPMB) and road-wear particles from road marking (RWPRM). RAMP is a diverse particle group both when it comes to particle properties and chemical compounds. Several studies have confirmed toxicity effects in experiments using TWP leachates at environmentally relevant concentrations according to known concentrations. However, more research is needed on the concentrations in the environment, uptake in biota for all three types of RAMP and the toxicity effects from these.