When chlorine is added to water it interacts with organic material to form a variety of cancer causing byproducts. Up to 17% of bladder cancers in the US are thought to be caused by these carcinogens, also known as disingection byproducts or trihalomethanes. If you’d like to know if these are in your water, simply look at the water report provided to you by your local water company. It will list trihalomethanes and haloacetic acids. Both of these groups of compounds cause cancer.
In an effort to reduce the amount of these disinfection byproducts in water many cities have turned to the use of chloramine, normally in the form of NH2CL. Chloramine is generally produced by adding ammonia to water containing chlorine. Chloramine is a weaker but more persistent and stable disinfectant that chlorine and so it remains in the distribution system longer, meaning the pipes that lead to your home.
The use of chloramine results in lower levels of the carcinogenic disinfection byproducts. Unfortunately chloramine produces its own set of byproducts, including nitroamines, iodo-trihalomethanes, and iodo-acids, which are also cancer causing. Skin irritation is a common complaint in cities where chloramines are in use. Chloramine use has other problems as well but the focus of this article is on health effects.
Chloramines are harder to remove from water than free chlorine. The carbon used to remove chlorine will not remove chloramine. And many water treatment dealers sell systems which use the wrong carbon in this situation. Chloramine removal requires the use of catalytic carbon. Chloramine is in fact so difficult to remove that I typically recommend both a whole house water filter and a kitchen water filter to do so. The whole house filter will remove the vast majority of chloramine, 95% or more, but a small amount will remain for removal by a drinking water filter.
There was a 37% increase in the use of chloramine by municipalities from 2010 to 2011 and 22% of people in the US are now estimated to be drinking water containing chloramines.
When purchasing a whole house water filter or drinking water filter first learn whether chloramines are present in your water and then purchase the appropriate filter to remove them. The presence of other contaminants in your water will also determine which type of filtration system will best serve you. See my website to learn how to choose the correct system to remove the contaminants in your water: www.cleanairpurewater.com