Abstract

Objective To comprehensively understand the pollution behavior of nanoplastic particles （NPs）（with a particle size smaller than 1 μm） is essential for grasping their environmental impact in the natural environment.

Progress This paper systematically outlines the sources and formation pathways of nanoplastics， the harm they cause to animals and plants， their interactions with microorganisms， and the combined toxicity effects and mechanisms of NPs with pollutants.Key sources of NPs include agricultural film usage， wastewater irrigation， and domestic sewage discharge. The formation process of NPs in the environment is more complex， involving multiple pathways such as photodegradation， chemical degradation，physical fragmentation， thermal degradation， and microbial degradation， with photodegradation and microbial degradation being the primary pathways. Research on the harmful effects of NPs on animals primarily focuses on aquatic environments， particularly in freshwater and marine ecosystems. In marine environments， the behavior of NPs involves agglomeration， adsorption，and the release of additives. NPs are also toxic to plant growth in soils， with studies focusing on their distribution in the soil environment， the mechanisms of root absorption in plants， and their modes of action. Current studies on the interactions between NPs and microorganisms have primarily focused on bacteria. NPs impact bacterial development by reducing growth activity， lowering enzyme activity， decreasing surface charge， and altering biofilm formation patterns. The interactions between NPs and

microorganisms in natural environments are complex， with their interplay relationships being more evident in water and soil environments. With increasingly more advanced research being conducted worldwide on the toxicological mechanisms of NPs， their effects on earthworms in soil， freshwater zebrafish， marine fish， and microalgae have emerged as hot spots. NPs are regarded as one of the most severe ecological threats， and their combination with pollutants， such as heavy metals， antibiotics， and chemical contaminants， presents even greater environmental hazards than NPs acting alone.

Conclusion and Prospects To further analyze and clarify the various environmental hazards posed by NPs， and to address the lack of basic data on their environmental impact， future research should focus on the following areas：1） Enhancing research on the interaction mechanisms between NPs and chemical pollutants， particularly the interactions between NPs and antibiotics in recent years；2） Developing high-precision， high-efficiency instruments to accurately detect plastic particles at the nanoscale or smaller， reducing their environmental impact；3） Improving the analysis of degradation products from NPs， particularly the detection of greenhouse gases such as CO₂ and CH₄ generated during degradation， to understand the impact of natural plastic aging processes on atmospheric greenhouse gas emissions.

Keywords：nanoplastic particle； environmental effect； toxicity mechanism； environmental behavior