Fate of road-dust associated microplastics and per- and polyfluorinated substances in stormwater

Emerging contaminants such as microplastics (MPs) and per- and polyfluorinated substances (PFAS) in the water environment have been documented as the major environmental threat due to their negative impact on the ecosystem. Road dust has been recognised as a potential source of these emerging pollutants in stormwater which are eventually released into open water bodies. The aim of this study was to identify the existence of MPs and PFAS in Australian road dust and stormwater samples. We found that different MP types such as polyethylene, nylon, polyester and cotton were identified in the stormwater samples. The main type of MPs in stormwater was microfibres which accounted for more than 50 %. It was also found that PFAS was detected in Australian road dust from industrial and heavily trafficked areas. Although there was no PFAS in stormwater in the selected industrial and heavy traffic study area, they can be found in airport and defence sites. This study indicated that road dust acts as the potential origin of MPs and PFAS in urban stormwater runoff.