Microplastics and Microrubbers in Soils Around Two Landfills and a Municipal Solid Waste Transfer Station in Ahvaz Metropolis, Iran

Background: Microplastics (MPs) and microrubbers (MRs) are a substantial source of pollutants entering the environment and a cause for debate in environmental studies in soils surrounding two landfills and a municipal solid waste transfer station near Ahvaz Metropolis. Since the current information about these particles in Iranian municipal solid waste transfer station and landfill systems is scanty, this study aimed to determine the amounts and abundance of MPs and MRs in soils. Methods: Each of the twelve sites that determined using a systematic grid sampling method had approximately 100 g of soil samples from a depth of 0-10 cm with three replications. The method used for extracting MPs from the soil samples was density separation with saturated zinc chloride solution. The particles were investigated by the size, shape, abundance and colour. A total of 1807 MP and 1872.7 MR particles were detected from the samples. The Pearson’s correlation coefficient (r) was used for describing correlations. Results: The highest abundance of MPs was observed at the S5 site (325.9±26.8 items/100 g soil). The particles were categorized into fragments, foams, fibers, films and spheres. Five ranges of particle size were identified (between 1 mm ≤L and L≤100 μm) in nine color categories. The 1 mm ≤L size class was dominant in MPs (54%) and MRs (52%). The majority of the MPs (41.8%) were white/transparent, whereas MRs were identified as black/gray (99.1%). Conclusion: Contamination by MPs and MRs exceeded allowable standards, compared to other transfer stations across the globe.