Microplastics in industrial and urban areas in South-West Iran

Plastics and their degradation products, microplastics (MPs), are ubiquitous in the environment, and urban and industrial soils may be the most polluted soils by this type of pollution. There is scarce information addressing human exposure to MPs from urban and industrial soils. This study assesses MP pollution in urban and industrial soils of two county capital cities in Iran, i.e. Abadan and Khorramshahr. The concentration of MPs ranged from 17 MPs/100 g industrial soil to 347 MPs/100 g urban soil, with a mean abundance of 122 MPs/100 g soil. Residential areas were the most contaminated by MPs among all the sampling sites. There, microfiber MPs, red and black, were the most abundant MPs, and it was also the case across sampling sites. Polyethylene terephthalate and polypropylene were the most common polymers among the investigated MPs, while nylon and polystyrene MPs were also present. Regarding MP sizes, those in the fraction 250–500 µm prevailed across all investigated sites. Estimated exposures to MPs through contact with the urban and industrial soils, for a normal scenario according to US EPA parameters, would lead to a daily intake < 1 MP for both adult and children, and their respective yearly intake of MPs is estimated in 6–127 and 12–253 MPs. Further research is needed to assess the health impact of current MP types and levels found in urban soil.