Accumulation of microplastic in road dust and in soil alongside roads – a case study from the Eastern Region, Abu Dhabi

Roadsides and soil have been sampled for microplastic content in 7 locations in the Al Ain area, Eastern Region, Abu Dhabi, UAE. The collection sites constituted residential areas and fall-out roads, but also one Wadi and the shoreline of a man-make lake. The concentration of micro-tire particles was found to be high on the roadsides of the residential areas. While a significant amount of tire macroparticles could be found on the roadsides of fall-out roads, these exhibited less micro-tire particles. Here, significant amounts of micro-tires could be found off-road, along the fallout roads, indicating, in absence of run-off water, Aeolic transport of the particles. The Wadi and the lakeshore sites were essentially free of micro-tires, but in all sites, microfibers were found. Collection of run-off water from roads during a rare rainstorm event showed transport of plastic microparticles both into the storm drains as well as to the adjacent soil. High surface temperatures and extreme aridity in the summer leads to the evaporation of small organic additives from the plastic materials leaving them dry and brittle. This leads to easy further mechanical fragmentation of the particles.