Another clip from your link says “Direct-exposure studies with early life-stage roach (from fertilized egg and juveniles) confirm that effluents induce a number of feminizing effects, including vitellogenin induction and duct disruption, in a concentration-dependent manner. “
Time*concentration will be the critical factor, I think; if the observed effects don't follow the amount of exposure (time*concentration) then there may be threshold effects, or it's a proof of homeopathy or hormesis (which I doubt).
I need to do “real work” for a while, but I'll keep a back-burner pot going looking for data on synthetic estrogen concentrations (there are too many sources of natural hormones).
Even if it can be shown that high-levels of synthetic estrogen correlate with high rates of intersexed fish, would you make the leap from correlation to causation?