I think swimming in 2-5ppm chlorine is much safer than not. I also think Weil means well, he's just such a naturalist it doesn't surprise me at all that he's against the 'evils' of chlorine. Now if your swimming in a shocked pool w/ppm up in the double-digits, it may cause some folks problems. I'd be interested in knowing to what extent we get absorption thru our skin for 1 hr/2 hrs. etc. at certain concentrations. Probably very small #'s.