Interaction between Microplastics and Pathogens in Subsurface System: What We Know So Far

Microplastics (MPs) are abundant in soil and the subsurface environment. They can co-transport with pathogens or act as vectors for pathogens, potentially causing severe ecological harm. The interaction of MPs with pathogens is an important topic. To describe the origins and features of MPs in the subsurface environment, we evaluated relevant studies conducted in the laboratory and field groundwater habitats. We explore the interactions between pathogens and microplastics from three perspectives including the respective physicochemical properties of microplastics and pathogens, external environmental factors, and the binding between microplastics and pathogens. The effects of some interaction mechanisms and environmental factors on their co-transport are discussed. The key factors affecting their interaction are the particle size, specific surface area, shape and functional groups of MPs, the zeta potential and auxiliary metabolic genes of pathogens, and the hydrophobicity of both. Environmental factors indirectly affect MPs and the interaction and co-transport process of pathogens by changing their surface properties. These findings advance our knowledge of the ecological behavior of MPs–pathogens and the associated potential health hazards.