Microplastic occurrence in urban and industrial soils of Ahvaz metropolis: A city with a sustained record of air pollution

This study investigates, for the first time, the concentration, distribution, fate and chemical composition of microplastics (MPs) in urban and industrial soils of Ahvaz metropolis, SW Iran. MP concentrations ranged from 100 to 3135 and 80 to1220 unit.kg(-1) in urban and industrial soils, respectively, with corresponding means of 619 and 390 unit.kg(-1). The most contaminated urban sites were located in the city center. Precisely these areas were affected by insufficient sanitation infrastructure including sewer systems, surface runoff collection and sewage treatment, and also high traffic loading in a commercial zone. MPs were found in various shapes, colours and sizes. In particular, microfibres (white-transparent and < 250 mu m) were the most abundant MPs found in urban (70%) and industrial (55%) soils. Based on the weathering observed in the MPs, a large number of them originated from the fragmentation of other plastics and could have been photobleached. Polyethylene terephthalate and nylon were the dominant polymers in the MPs found in both industrial and urban soils and they could originate from textiles and tyres.

Automated summary

This study investigates the concentration, distribution, fate, and chemical composition of microplastics in urban and industrial soils in Ahvaz, Iran. The study found higher concentrations of microplastics in urban soils, particularly in the city center, which may be attributed to insufficient sanitation infrastructure and high traffic loads. Microplastics were found in various shapes, colors, and sizes, with microfibers being the most abundant. The dominant polymers in the microplastics were polyethylene terephthalate and nylon, which could originate from textiles and tires.