A Love Hate Relationship with Chlorine

By Christina Reed of Discovery News


Chlorine is the anti-hero of disinfected drinking water. A pathogen-killer with that fresh swimming pool scent, the green gas has kicked cholera and e. coli to the curb in most developed nations. In recent years however, chlorine’s “dark side” – a tendency to increase the rate of bladder cancer and miscarriages – has prompted water treatment facilities to shun the chemical and turn to alternative disinfectants.

The results of this switch have proved toxic in some cities, such as in Washington D.C., where the use of chloramine, the ammonia diluted version of chlorine, allowed lead to leach from city pipes into the drinking water. Chlorine, with its oxidizing powers that could coat lead pipes with a less soluble compound, would never have let that happen to our nation’s capital.

It would have just quietly waited for the remnants of WWI ammunition to take the blame or perhaps chromium-6. While there is no danger from the recovered WWI artifacts, chromium-6 is currently under review.

EPA Administrator Lisa Jackson met in late December with senators from several states to announce a detection plan for testing chromium-6 contamination in the nation’s drinking water and likely revise drinking water regulations accordingly.

Today, it is not clear whether the risks of sticking with chlorine, or the costs associated with techniques that can minimize its bad behavior, outweigh the slough of new problems that are arising from chlorine’s abandonment and the use of alternative treatments, caution environmental engineers from the United States and Switzerland in the Jan 7, issue of Science.

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