Microplastics in landfill leachates: The need for reconnaissance studies and remediation technologies

Although landfills represent repositories for cumulative loading of plastic waste derived from households and industrial sectors, often seen as sinks, the contribution of these structures and their leachates as potential sources of microplastics to natural environments remains poorly covered. Microplastics discharged from these sites may pose greater risks to human and environmental health by adsorbed toxic and persistent hazardous chemicals. As reviewed here, landfill leachates present microplastic concentrations of 0–291 particles L−1, highly variable depending on landfill conditions and methodologies adopted, while treatment of leachates can reduce these concentrations in 1–2 orders of magnitude. Nonetheless, knowledge is still scarce on the factors influencing the release of microplastics from landfills, and technology must be developed to mitigate this source of microplastics, which poses a significant challenge but is needed in order to preserve a good environmental status.