Epidemiological association between chlorinated water and overall risk of cancer: A systematic review.

Public large scale use of chlorine-disinfected water began in the early years of the 20th century and resulted in dramatic reductions in observed rates of dysentery causing diseases, particularly cholera and typhoid infections 1 . Today in the USA 98% of water treatment plants use chlorine-based disinfectants to treat water 2 and similar chlorine disinfection use patterns of water treatment occur around the world where developed systems of potable water exist. The clear reduction in dysentery causing diseases derived from chlorine disinfection of water supplies offset complaints about chlorination adversely influencing the taste of water, environmental impacts and concerns regarding potential adverse health effects 1,3-8 .