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?
I recall a while ago there were frogs with limb deformities, and the reports on its cause ranged from the Ozone Hole to pesticides to Global Warming. Ultimately it turned out to be a fungus or something natural, and the issue was dropped from the press.
This issue is a political issue as well as a technical one, and each political force will be trying to influence the pool of available data, and will try to steer research into areas that sport their POV. This makes it hard to figure out what's really happening, especially since we can only use other people's data. It's much easier to measure cosmic-ray induced upsets in a static RAM in orbit.
There are the religious people, the “whole and natural” people, Luddites in general, pharma companies, the “free sex” people, feminists, both sides of O’Riley’s Culture War, and probably many other groups with a stake in feminized fish and rodents with small testes.