Microplastic Abundance in Human-Influenced Soils in Recreational, Residential, and Industrial Areas

Plastic pollution is a now global problem that affects terrestrial, marine, and freshwater ecosystems. Small plastic particles (< 5 mm) are considered as microplastics (MPs) which can originate from primary and secondary sources. Microplastic pollution in terrestrial ecosystems is crucial since their abundance and flow are expected to be higher than aquatic systems. This research investigates the abundance and evaluation of current microplastic abundance in human-influenced soils to reveal the impact of different anthropogenic activities on soil MP contamination. Three main categories as industrial, residential, and recreational areas were considered, and samples from different land-uses for each category were collected in Istanbul, Turkey, and examined. Results showed that residential areas had the lowest MP content (mean = 3378 items/kg), while the highest abundance was found in recreational zones (mean = 7956 items/kg). The abundance of MPs in industrial areas was between these groups with a mean value of 4488 items/kg. The lowest concentration was observed in one of the residential zones with 1868 items/kg, and surprisingly, the highest content was found in a forestal recreational area (Belgrad forest) with 9332 items/kg. Shape ratios of particles were different for each category. Round/spherical particles had the highest share in industrial and residential areas with 34% and 32%, respectively, and fibers in recreational areas by 36%.