Unraveling the complexities of microplastics and PFAS synergy to foster sustainable environmental remediation and ecosystem protection: A critical review with novel insights

• Common daily life products of humans are co-sources of Microplastics and PFASs. • Electrostatic and hydrophobic interactions are key adsorption mechanisms. • MPs, PFAS characteristics, and environmental factors influence their interactions. • Combined toxicity leads to oxidative stress and reproductive system disruption. • Further investigation is needed to develop effective combined removal strategies. Microplastics (MPs) and polyfluoroalkyl substances (PFASs) have emerged as emerging contaminants, drawing global attention due to their persistence and extensive presence in ecosystems. Although comprehensive studies exist on their individual behavior, their synergistic interactions remain unexplored, necessitating in-depth investigation to understand their impacts on environmental compartments. This review investigates the combined sources of MPs and PFASs, including commonly used daily products of human and wastewater treatment plant effluents, which release approximately 7.2 billion microplastics daily into aquatic environments and PFAS concentrations ranging from 8.1 to 24 µg/person/day. The review also discusses the mechanisms and environmental parameters that govern PFAS sorption over MPs. Studies indicate that the efficiency of PFAS retention increases with smaller, aged, or biofilm covered MPs due to larger surface areas, with adsorption rates varying from 20% to 85% depending on the type of MP and environmental conditions. Furthermore, the review explores the trophic transfer and combined toxicity of these contaminants, demonstrating that MPs act as carriers for PFAS, affecting their distribution, accumulation, and impact within ecosystems. These interactions can severely affect aquatic species, causing intestinal damage, oxidative stress, and disrupted reproductive systems in fish and other organisms. Despite these findings, significant knowledge gaps remain in understanding their interactions in complex ecosystems, particularly in terrestrial environments. Addressing these gaps requires developing standardized detection methods and conducting studies under realistic environmental conditions. Finally, this review suggests that future research should focus on developing combined removal strategies and source abatement measures to effectively manage the associated environmental and health risks.