Gathering at the top? Environmental controls of microplastic uptake and biomagnification in freshwater food webs

Microplastics are ubiquitous in the environment, with high concentrations being detected now also river corridors and sediments globally. Whilst there has been increasing field evidence of microplastics accumulation guts tissues freshwater marine aquatic species, uptake mechanisms into food webs, physical geological controls on pathway-specific exposures to microplastics, not well understood. This knowledge gap is hampering assessment exposure risks, potential ecotoxicological public health impacts from microplastics. review provides a comprehensive synthesis key research challenges analysing environmental fate transport ecosystems, including identification hydrological, sedimentological particle property microplastic ecosystems. mechanistic analysis outlines dominant pathways for ecosystems identifies potentially critical entry associated contaminants webs as their risk accumulate biomagnify. We identify seven that, if overcome, will permit advancement beyond current conceptual limitations provide process understanding required assess exposure, uptake, hazard, overall systems humans, insights priority impact support management decision making.