Microplastics pollution modulating soil biological health – A review

Microplastics (MPs) reach the soil environment through the application of recycled water, biosolids, and compost and the in-situ weathering of plastic mulch used in agriculture. This review provides an overview of the sources of MP input to soil and their interactions with soil biota, thereby impacting soil biological health. MPs contain various chemical additives and can be ingested by soil biota, thereby impacting their activity and function. MPs also serve as a vector for inorganic and organic contaminants. These chemical additives and environmental contaminants can be released into soil porewater during the weathering of MPs in soil and impact soil biota. Overall, MPs can also alter soil's physical and chemical properties thereby impacting the habitat for soil microorganisms. Soil microorganisms can use MPs as a carbon source and porous habitat for proliferation. Future research needs to focus on the genomic and functional diversity of soil microbes as impacted by MP contamination, thereby enabling us to develop strategies to mitigate the impacts of MP on soil biological health.