Disinfecting water is an important stage of the water treatment process and is used commonly around the world. Chlorine is a common disinfectant as it effectively prevents the re-growth of bacteria and other pathogens.
However when chlorinated water is ingested it can cause eye, nose and sinus irritations as well as stomach problems. When chlorinated water is used in cooking, the chlorine vaporizes and can quickly infiltrate the air; inhaling this vapour is the leading cause of asthma. Chlorinated water is also harmful when showering as it magnifies the effects of chlorine inhalation as chlorine levels are concentrated.
Chlorine also produces many harmful by-products when combined with water; these by-products include bromate, chlorite, haloacetic acids and trihalomethanes (THMs). When water containing these by-products is ingested the results can be more dangerous than chlorine itself, as many of these by-products have been linked to cancer and many other health problems.
