Chlorine Causes Cancer . . . or Not!

[aylad]

My favorite of these--I think it was the one about using moss--was the one that stated that if there were no iron in the water, then microbes couldn't grow. Hmmmm--maybe we should re-think iron filtering----NOT

Janet

[BigTallGuy]

O.K. riddle me this. Municipalities across the country regularly add chlorine to our drinking water. Shouldn't we be more afraid of cancer from DRINKING the chlorinated water as opposed to SWIMMING IN IT?

[chem geek]

Yes and no. Generally speaking inhalation of volatile compounds can get into the bloodstream more readily than through drinking of water that has to go through rather harsh acidic conditions in the stomach first and then on to differing levels of absorption mostly in the small intestine where digestive enzymes can break down some of the chemicals. On the other hand, the quantities of water that one drinks is higher than the amount of by-products one inhales.

Drinking water is processed through multiple stages that intentionally try and reduce organic precursors before the later chlorination stages. Filtration (including coagulation), aeration, and non-chlorine chemical processes are done before chlorine is added for disinfection. The final stage will add either chlorine or monochloramine with more water utilities moving to the latter to avoid more disinfection by-product formation downstream in the distribution system and to have this residual protection last longer.