Research Information System
Physics and Chemistry of the Earth, vol.143, 2026 (SCI-Expanded, Scopus)
Biodegradable plastics, derived from renewable materials, are promoted as environmentally friendly alternatives to conventional petroleum-based plastics. However, these materials fragment into biodegradable microplastics (Bio-MPs) during environmental breakdown, raising concerns about incomplete mineralization and their potential to interact with co-pollutants such as antibiotics. Despite widespread use, how Bio-MPs interact with antibiotics during environmental aging remains poorly characterized. This review synthesizes evidence demonstrating that aging through UV exposure, mechanical wear, and biofilm formation significantly enhances Bio-MP adsorption capacity for antibiotics, often exceeding that of conventional microplastics. This enhancement occurs through increased surface roughness, porosity, and oxygen-containing functional groups, while biofilm formation provides additional binding sites via extracellular polymeric substances. Adsorption efficiency is governed by multiple mechanisms including hydrophobic partitioning, electrostatic interactions, and hydrogen bonding, with performance further modulated by environmental factors including solution pH, ionic strength, and dissolved organic matter. Crucially, this enhanced sorption capacity transforms Bio-MPs into mobile vectors that facilitate antibiotic transport, creating localized hotspots for antimicrobial resistance gene dissemination in aquatic systems. This risk dimension has been previously overlooked in life-cycle assessments, challenging the assumption that biodegradable equals environmentally safe. Addressing this requires comprehensive frameworks that account for contaminant-carrying potential during the microplastic phase. However, quantitative risk assessment remains constrained by laboratory studies at non-environmental concentrations, underrepresentation of sediment systems, and lack of field evidence linking Bio-MP-antibiotic complexes to resistance gene transfer. To determine whether biodegradable plastics reduce or worsen pharmaceutical pollution, future studies should map breakdown routes, evaluate resistance to antimicrobial agents, and confirm real-world settings.