When 1 + 1 ≠ 2: How mixed water contaminants rewrite toxicity rules

Pesticides and disinfection by-products are widely detected together in treated drinking water at trace levels worldwide. Both groups are associated with long-term health risks, including cytotoxicity and genotoxicity, raising concern about chronic exposure. Current regulatory prioritization largely relies on additive toxicity assumptions, ranking chemicals by their individual toxicity-weighted concentrations.