Published: June 2, 2015

    Chlorine Treatment No Guarantee Against Pathogens

    Chlorine has, for years, been the go-to solution for disinfecting public water. Thanks to such disinfectants, the United States has a fraction of the water-borne diseases seen in countries with limited access to clean water.

    Nature, however, is nothing if not reactive. Just as over-exposure to antibiotics has created new strains of drug-resistant “super bugs,” so too are some microorganisms developing a resistant to chlorine, raising Americans’ risk of hepatitis, Legionnaires’ disease, gastroenteritis, and cryptosporidiosis. Worse yet, chlorine-resistant bacterial strains are often resistant to antibiotics as well.

    Why is This Happening?

    Quite frankly, we’re in a constant arms race with microorganisms. As we develop new methods to control or destroy them, the microorganisms undergo natural selection. Those microorganisms with any degree of resistance to chlorine are most likely to survive long enough to replicate, passing their resistant genetic code on to future generations and resulting in ever more resistant descendants.

    It’s really no different than a farmer breeding beef cattle for specific traits—except we haven’t been doing it intentionally. We’ve simply provided the microorganisms with an obstacle—chlorine—to overcome, and some of them have proven more than up to the challenge. Cryptosporidium, for instance, can survive up to ten days in a heavily chlorinated swimming pool, while chlorine offers little protection against Guardia.

    Protecting Yourself

    Ultraviolet treatment does an excellent job of killing chlorine-resistant microorganisms. Ultraviolet rays disrupt a microorganism’s DNA, destroying its ability to replicate. As it can no longer reproduce, the virus, bacteria, or parasite is no longer a threat to your health.

    Sadly, public water facilities have limited access to UV technology. To ensure your water is safe, it’s necessary to have a whole house filtration system that includes UV purification. If not, you could discover firsthand how serious chlorine-resistant microorganisms can be.