Combined exposure to aquatic pollutants (e.g., chemicals, ZnO nanoparticles, acid rain) intensifies their individual effects. Studies demonstrate that co-exposure to pollutants like ZnO nanoparticles and microplastics is more detrimental than single-pollutant exposure. Acid rain and nanoparticles can accelerate leaf litter decomposition, and nanomaterials negatively affect aquatic organisms. Understanding these synergistic effects is crucial for assessing pollutant impacts on aquatic ecosystems. Given the millions of existing toxic pesticides, chemicals, and their metabolites, the future health of these ecosystems until 2050 is concerning.