Fate of plastic nanoparticles (PNPs) in soil and plant systems: Current status & research gaps

Nanosized plastic particles are emerging pollutants in soil, plants, and water resources, and a global environmental concern of the 21st century, as evidenced by widespread investigations and community awareness. In particular, plastic nanoparticles (PNPs, defined here to have sizes ranging from 1 nm to 1000 nm) can be produced during mechanical abrasion, photochemical oxidation, and biological degradation of microplastics (1 μm to 5 mm). To date, the ecological fate, toxicity, and possible risks related to PNPs have received far less attention than microplastics. This review mainly focuses on two different aspects; one is the interaction of PNPs with soil and the second is PNPs in the plant system. Interaction of PNPs with soil discussing the different factors associated with PNPs mobility in soil and how it affects the microbial community. The review also examines the co-transport of other contaminants with PNPs in soil. And the remaining half of the review showed the potential of PNPs to enter plant systems and affect them at molecular, biochemical, and physiological levels. Based on the currently limited data and uncertainty regarding the actual impact of PNPs on soil and plant systems, suggested considerations to address key knowledge gaps are delineated.