Is the chlorine that is administered to public water enough to have any biological effect on the human body?

Question

In otherwords, is it, in the amounts dosed into our public water, sufficiently concentrated as such to be carcinogenic or mutagenic to cells? If so, which cells? What organs could it feasibly damage? Could the brain be a target?

Answer 1

I am somewhat reluctant to give you this information since you seem to obsess about this.  :-)  The main problem with chlorinating drinking water is that it forms trihalomethanes (THMs) for short), in particular, chloroform.  Chloroform is listed as a human carcinogen and its concentration in drinking water is regulated by EPA standards.  There are lots of essentially crackpot websites out there linking THMs in drinking water with virtually every affliction known to modern man.  However, there aren't very many reputable studies showing a definitive link between chlorinated drinking water and any adverse health effects.  What is known definitively is that if you don't chlorinate drinking water, you get all sorts of really nasty bugs and parasites running around in the water supply that *will* kill you dead or make you very sick.  

If you google around  for "trihalomethanes drinking water" you will find tons of stuff out there.  Be very discriminating on what you believe, strident shrill websites claiming horrible effects from chlorination are for the most part wrong.  THMs are an issue, but one that municipal water providers are aware of and actively control, and the risk of cholera, cryptosporidium, and e.coli contamination in drinking water is far more severe.