Abundance and characteristics of microplastics in different zones of waste landfill site: A case study of Hamadan, Iran

Abstract

Microplastics are an emerging environmental concern that threatens the lives of humans and other organisms. Landfills are reservoirs for the production and accumulation of microplastics because the plastic waste disposed in them turns into microplastics over time under the influence of environmental and chemical conditions. This study is the first report on the abundance and characteristics of microplastics based on size, shape, color, and chemical composition in different old and active zones of the Hamadan landfill. The results clearly showed that the abundance of microplastics is significantly higher in leachate lagoon zone and old waste sites than active and virgin sites. Accordingly, the abundance of microplastics in the leachate lagoon zone, the old municipal and medical waste site, and the active municipal and medical waste site were found to be 76513, 39813, 26900, 16940, and 18766 items/kg dry soil, respectively. The abundance of microplastics in sizes 0.45 μm–25 μm and 25 μm to 5 mm was 59.32% and 40.68%, respectively. In addition, black microplastics were identified as the most abundant color (49%). In terms of shape classification, fiber microplastics were the most abundant (71%). Also, the most abundant chemical composition among microplastics belonged to LDPE (35%) and HDPE (33%) polymers. The findings of this study showed that the abundance and characteristics of microplastics in different landfill zones are quite diverse, which will have an important impact on proper waste management and prevention of environmental pollution.