Assessment of the hazard effect of an environmental pollutant, (2-OH-BDE 123) using zebrafish embryos.

Abstract

In the recent decades, many environmental pollutants have received significant attention due to their potential ability to mimic the actions of endogenous estrogens. These pollutants are referred as environmental estrogens and are suspected of causing health effects in both humans and wildlife through disruption of the endocrine system and causing male reproductive dysfunction, thus they are classified as endocrine disrupting compounds (EDCs) such as phenolic metabolites. To monitor general toxicity of this class of EDCs, embryos of zebrafish were exposed to gradual concentrations of 2-OH-BDE 123 (hydroxy-brominated diphenyl ethers). Exposures were done by immersion of 1 hour post fertilization (hpf) zebrafish eggs to 72 hpf, nominal concentration range of 0.03 : 2.5 μM. Embryos/ larvae were assessed daily for death and structural defects. Results revealed that concentrations from 0.3 μM of such metabolites were toxic to the developing zebrafish causing serious morphological alterations and internal deformations. Both toxicity incidence and potency were correlated with the concentration applied. In conclusion, these compounds induced several teratogenic effects. More studies are required for a proper risk assessment and more attention should be given to this class of chemicals in the aquatic environment.