it's probably studies like this that will affect policy rather than consumer decisions which are driven by populism.
http://www.sciencedaily.com/releases/2003/12/031219072830.htm
According to the study, published in the online version of the scientific journal Environmental Health Perspectives, the male fish had one-third less testosterone and their testes were about half as big as those of unexposed fish upstream. The female fish had about 20 percent less estrogen and 45 percent more testosterone than females from the uncontaminated stream.
not sure why both would have less of a different hormone if there are probably more male cattle being fed (breakdown?)
seems like if i was a peer reviewer, i would have had them expose fish to increased levels of each hormone independently and in concert with ratios found in the feedlot as controls before publication. but, i guess it didn't fit the agenda.
"In contrast to humans, aquatic wildlife is exposed to an unknown concentration of synthetic and natural hormones excreted by the cattle."
this wouldn't be that hard to calculate or emulate.
i hate how they can ALWAYS get away with using words like UNKNOWN, whose intent is so clearly obvious, and in my book, irresponsible.
i wonder how these fish evolved when the bison herds, mammoths, and dinosaurs trumbled through the streams. i'd hate to have a brachyosaurus poop legislated out of the waterways.
on the other hand, i'm not for putting feedlots next to streams and think producers do and should use sediment/nutrient traps, which, have been show to work by they same journal.