Uptake of estradiol from sediment by hornyhead turbot (Pleuronichthys verticalis) and effects on oxidative DNA damage in male gonads

Male and female hornyhead turbot (Pleuronichthys verticalis) were exposed to four concentrations (0, 0.75, 14.7 and 46.5 ng/g dry weight) of E2-amended sediment for 7 days. Sediment-derived E2 was bioavailable to the flatfish, though the route of uptake was unclear. A concentration of 46.5 ng/g E2 in sediment led to a significant increase in vitellogenin concentrations in the plasma in both sexes after 7 days of exposure. Though plasma E2 concentrations increased significantly in males at sediment E2 concentrations of 0.75 ng/g dry weight and above, a dose-dependent increase was not observed. There was also no correlation between sediment E2 concentrations, plasma E2 concentrations, and oxidative DNA damage in male gonads. The results suggest that the DNA damage previously seen in the gonads of feral hornyhead turbot at a sewage outfall is likely not caused by acute exposure to exogenous E2 from sediments.