Effects of humic substances on the aqueous stability of cerium dioxide nanoparticles and their toxicity to aquatic organisms

The impacts of humic substances (HS) on the aquatic stability and toxicity nano‑cerium dioxide (nCeO2) to three organisms with different exposure characteristics were investigated. Addition HS suspensions nCeO2 lowered surface zeta potential particles, reduced their hydrodynamic size, increased energy barrier as indicated by total profile. This resulted in a more stable suspension compared without added. Moreover, higher concentration further stabilized suspension. Acute unicellular green alga Raphidocelis subcapitata crustacean Chydorus sphaericus was lower acute zebrafish (Danio rerio) eleutheroembryo other hand significantly enhanced (additive synergistic) upon increasing concentration. Our findings emphasize that is important stabilize nano-suspensions its impact differs across organisms. Emphasizing each selected from trophic levels can explain how particle toxicity.