Toxicokinetics Reveal Structure-Related Differences in Developmental Toxicity among Typical Aromatic Disinfection Byproducts in Zebrafish Embryos

However, in vivo toxicokinetic behavior of aromatic DBPs during sensitive developmental stages remains poorly understood, limiting accurate risk assessment. Here, five aromatic DBPs within three classes (halophenols, halonitrophenol, and halohydroxybenzaldehydes) were systematically investigated using zebrafish embryos to compare developmental toxicity and characterize toxicokinetics.

Developmental toxicity tests showed that the median lethal concentrations (LC₅₀) of halonitrophenol were lower than halophenols and halohydroxybenzaldehydes, and brominated analogues were consistently more toxic than chlorinated counterparts. When expressed as median lethal residues (LR₅₀) instead of LC₅₀, toxicity differences decreased from 13-fold to 3-fold, indicating that reliance on external concentrations may misrepresent toxic potency.