Plastic and Microplastics in Soil Systems: Sources, Environmental Impacts, and Future Perspectives – A Review

Abstract

The article examines the increasing vulnerability of soils, groundwater, land resources, agricultural systems, freshwater bodies, and the marine environment to plastic and microplastic contamination. Microplastics are widely distributed in the environment due to the physical and biochemical degradation of plastic products. Although previous studies have primarily investigated plastic from ecological, chemical, agricultural, and public health perspectives, this review emphasizes the importance of integrating civil engineering into the discussion. This analysis synthesizes finding multiple studies to evaluate the occurrence, persistence, and degradation behavior of plastic and microplastic in soils. Particular attention is given to the role of solid waste disposal systems, especially landfills, as a potential source of environmental contamination. From a geotechnical standpoint, the design and management of such facilities are examined to highlight the possibility of microplastic migration from landfills into surrounding soils and the environmental system. Furthermore, the study discusses additional sources related to civil engineering practices, including the use of plastic-derived materials in construction applications such as tire chips, polyethene terephthalates (PET), waste foundry sand (WFS), and dredge sediments used as engineering fills. Overall, the article underscores the dual role of plastic waste in civil engineering as both a potential environmental contaminant and as a material resource and outlines future research directions aimed at mitigating the impact of plastic pollution on geotechnical and civil infrastructure systems.