Chlorine is a highly effective and inexpensive disinfection agent used extensively to treat municipal water supplies. It has played a key role in eradicating water–born infectious diseases such as typhoid and cholera.
Unfortunately, a growing body of evidence indicates that the practice of using chlorine to treat municipal water supplies may be very hazardous to human health, especially when high levels of free residual chlorine leave the water treatment facility and arrive to your tap.
One such dangerous after-effect of chlorine use is the formation of disinfection by-products (DBPs). DEPs are formed when chlorine is used to disinfect water. One class of these chemical compounds is called trihalomethanes (THMs), which are formed when chlorine reacts with the organic matter found in water. THMs have been known to damage the kidney, liver, and nervous system and to cause birth defects.
A recent study conducted by doctors at Harvard University in collaboration with the University of Wisconsin found that DBPs are responsible for increasing the rate of rectal and bladder cancer diseases.
The culprit, once again, is chlorine which the doctors claim caused a noticeable increase in low-density lipo-proteins (bad cholesterol) which as been linked to both rectal and bladder cancer.
In addition, many other scientists are convinced that chlorinated acids such as MX and DCA are the most dangerous chemicals one can be exposed to. Both are found primarily in chlorinated water. Not only is drinking chlorinated water dangerous, but hot showers and baths can release 50% of dissolved chlorine and up to 80% of THMs which are then breathed into the lungs or absorbed into the body through the skin.
"We are quite convinced, based on these studies, that there is an association between cancer and chlorinated water."
Medical College of Wisconsin Senior Research Team
It is not uncommon to find more chlorine in tap water than is recommended safe for your swimming pool.
"Cancer risk among people drinking chlorinated water is as much as 93% higher than among those whose water does not contain chlorine."
According to the U.S. Council of Environmental Quality
"We are learning the hard way that all the time we thought we were preventing epidemics of one disease we were creating another. Two decades after the start of chlorinating our drinking water the present epidemic of heart trouble and cancer began."
Dr. Joseph M. Price PhD
"Up to 2/3 of the harmful effects of chlorine are due to inhalation and skin absorption while showering."
The American Journal of Public Health