Microplastics in Soils: Sources, Fate, Toxicity, and Remediation Technologies

Microplastics (MPs) are ubiquitous pollutants that are found in soils around the world. Their sources include sludge, compost, irrigation water, and spillovers from urban areas. They can influence soil physical and chemical properties such as density, pH, and water retention capacity. Due to their small size, MPs can block pores within plants and affect their growth. Soil organisms not only move and redistribute MPs within the ground but help degrade MPs, albeit slowly. The ingestion of MPs by farm animals and the presence of MPs in plants raise the possibility of MP transfer to the human food cycle. As plastics have long life spans in the environment, remediation methods will only have a marginal effect. Thus, the substitution of plastic materials in mulch films and netting and decreasing MP input from compost and sewage sludge has become a matter of urgency.