All dioxins contain chlorine... and that is why we do not want to take fulvic\humic substances in chlorinated water... we end up making our own dioxins. Chlorinated pools form dioxins... so can chlorinated drinking water.
This does not negate the possibility that MH may be correct, at least in part, in his assumption\observation, even though there was very likely more than one factor involved.
Anything, and I mean anything, and everything we are exposed to, or choose to do, affects our genetics... and ultimately what we pass onto our children.