Ben:
I have to contradict you:
A small extreme portion of the environmentalists are anti-chlorine--but those people are against ANY chemical usage, as irrational as that sounds.

I like to think of myself as somewhat environmentally aware and responsible (Hey! MY pool is heated with sunshine--as "green" as it gets!) but I would never advocate dropping chlorine usage until a PROVABLE replacement of similar quality is available--and bromine ain't it!