Estrogenicity of butylparaben in rainbow trout Oncorhynchus mykiss exposed via food and water

After 12 days exposure to 35 and 201 μg butylparaben l−1, plasma concentrations were 9 and 183 μg l−1, respectively, and for the fish exposed to 201 μg l−1 there was a positive correlation between concentrations of vitellogenin and butylparaben in the plasma. On the assumption that butylparaben removed from the water phase during water exposure were taken up into the fish, butylparaben uptake rates in the fish exposed to 35 and 201 μg butylparaben l−1 were 13 and 78 mg kg−1 day−1, respectively.