City municipalities the world over add chlorine to water being used for human consumption with the objective of ridding the same from microbes. The truth is that the disinfectant though inexpensive and effective is being criticized for posing health risks. In this article we discuss the information related to benefits and points of caution related to chlorification of water.

What is Water Chlorination?

The process by which chlorine is added to water is termed as water chlorination. Chlorine is introduced to water to kill bacteria and other microbes that may be present in tap water. Chlorine has played an instrumental role in preventing the spread of water borne diseases like cholera, jaundice, typhoid and dysentery.

It was as early as 1894 that it was proposed that chlorine can be added to water to make it free from disease causing microbes and subsequent research confirmed this. It was in 1905 that permanent chlorification of water was started. A fault in the water supply system in the city of Lincoln, England led to a serious outbreak of typhoid. Chlorine was introduced to water to curb the spread of the epidemic and since then it became an integral part of water supply systems.

The goodness of Chlorine

When chlorine is used with modern filtration techniques it is effective against nearly all microorganisms. Easy to use and highly effective small traces of chlorine remain in the water as it travels from the source to the tap. This plays an instrumental role in ensuring that water is not contaminated again.

Chlorine considered an essential when it comes to disinfecting drinking water is also being criticized for posing health risks. DBPs (Disinfection by-products) are known to pose health risks.

Chlorine and Cancer

City municipalities the world over add chlorine to water being used for human consumption with the objective of ridding the same from microbes. The truth is that the disinfectant though inexpensive and effective is being criticized for posing health risks. Chlorine was used as a weapon during WWI. It would burn the lungs and other tissue when inhaled. Use of chlorine is is being linked to higher incidence of cancers affecting the bladder, rectum and breast. Chlorine leads to formation of trihalomethanes (THMs) which encourage the growth of free radicals.The water that we intake tends to stay longest  in the bladder and the rectum and high presence of THMs can be harmful for these organs. Women with breast cancer have been found to have higher levels of organochlorines which are again chlorine byproducts.

The truth

There is no definite evidence that suggests that the health risks are greater than the benefits. A number of researches have indicated a weak association between DBPs and various cancers. Efforts are on to reduce the DBPs but not at the cost of disinfection. The risk posed by DBPs is considerable less as compared to the presence of pathogens in potable water. Chlorine can lead to health complications but evidence associated with the negative effects is limited.

What to do?

As discussed above chlorine offers both benefits as well as negatives. Opting for bottled water may not be the best option. Water companies like municipalities largely use chlorine to treat water. Some steps that can be taken are:

• Opting for a carbon based water filter: Carbon present in the filter absorbs the chlorine and contaminants before it is poured for drinking.
• Resorting to ozone treatment: Some companies and municipalities are rapidly moving to supplying water treated with ozone. The only deterrent in the case of ozone is the cost factor involved.
• Allowing the water to rest:  It is also suggested that water be allowed to rest for 24 hours before consumption. The idea is to give the water time to let the gas off before it is ingested.

We suggest that let us have a water supply system where we can consume pristine water. This entails that water bodies be kept clean and we work to prevent contamination of ground water. Effective steps for abatement of pollution need to be take Water pollution needs to be checked the world over.