A state-of-the-art review of environmental behavior and potential risks of biodegradable microplastics in soil ecosystems: Comparison with conventional microplastics

As the use of biodegradable plastics becomes increasingly widespread, their environmental behaviors and impacts warrant attention. Unlike conventional plastics, their degradability predisposes them to fragment into microplastics (MPs) more readily. These MPs subsequently infiltrate the terrestrial environment. The abundant functional groups of biodegradable MPs significantly affect their transport and interactions with other contaminants (e.g., organic contaminants and heavy metals). The intermediates, and additives released from depolymerization of biodegradable MPs, as well as coexisting contaminants, induce alterations in soil ecosystems. These processes indicate that the impacts of biodegradable MPs on soil ecosystems might significantly diverge from conventional MPs. However, an exhaustive and timely comparison of the environmental behaviors and effects of biodegradable and conventional MPs within soil ecosystems remains scarce. To address this gap, the Web of Science database and bibliometric software were utilized to identify publications with keywords containing biodegradable MPs and soil. This review comprehensively summarizes the transport behavior of biodegradable MPs, their role as contaminant carriers, and the potential risks they pose to soil physicochemical properties, nutrient cycling, biota, and CO