Micro and nanoplastics in terrestrial ecosystems: pathways, health implications, and mitigation strategies

Micro- and nanoplastics (MNPs) are increasingly recognized as persistent contaminants in terrestrial landscapes, with agricultural soils serving as significant reservoirs and secondary sources. The primary sources of these inputs include mulching films, tire and road-surface degradation, wastewater sludge and compost application, synthetic textiles, and atmospheric deposition, resulting in persistent accumulation in both managed and natural soil environments. Upon incorporation into the soil matrix, MNPs undergo fragmentation, surface aging, and biofilm development, which collectively alter their physicochemical characteristics, mobility, and interactions with soil minerals, organic matter, and microbial consortia. Empirical and field-based investigations demonstrate that MNPs can modify soil structure and nutrient-cycling dynamics, hinder plant growth, disrupt rhizosphere functions, and promote the uptake and translocation of nanoscale particles by roots, raising significant concerns about potential transfer within food chains. Emerging toxicological research further indicates the potential for oxidative stress and inflammatory responses associated with nanoplastic exposure; however, quantitative assessments of exposure-relevant risks in terrestrial systems remain notably limited. This review transcends mere descriptive synthesis by systematically integrating current evidence into a source-pathway-transformation-exposure-risk framework specifically designed for terrestrial ecosystems.