Thyroid Hormone Levels Alteration in Sole (Cymoglossus robustus) Exposed to Polybrominated Diphenyl Ethers

Juvenile sole (Cymoglossus robustus) were exposed to BDE-47 and BDE-99 through feeding in the laboratory for 60 days, followed by 60 days of clean food, to examine bioaccumulation and potential thyroid hormone disruption effect. The results show that both BDE-47 and BDE-99 accumulate in fish tissues. The free tri-iodothyronine (T3) concentrations in the plasma of sole varied significantly throughout the experiment but were not related to PBDEs exposure. In contrast, plasma levels of thyroxine levels (T4) were lower in both groups of PBDE-exposed fish compared with control fish after 60 days of exposure, suggesting that PBDEs may influence thyroid homeostasis.