Source Water Contaminants
These contaminants include arsenic, asbestos, radon, agricultural chemicals, and hazardous waste. Of these, the strongest evidence for cancer risk involves arsenic, which is linked to cancers of the liver, lung, bladder, and kidney.
Using chlorine to treat water helps to reduce the risk of infectious disease but, may account for a substantial portion of the cancer risk associated with drinking water. The by-products of chlorination have been associated with increased risk of bladder and rectal cancer. Fluoridation of water has received a lot of scrutiny but to date does not appears to pose cancer risks.
Further research is needed to identify and quantify risks posed by contaminants from the water distribution networks, including the biologically active micropollutants, such as microbial agents. In some U.S. cities, these distribution networks are hundreds of years old and are comprised of dubious materials.
To find out about the source of your water before distribution go to the Environmental Working Group (EWG) website and see the 2019 EWG Water Database.
a RPE – ENVIRONMENTAL KNOWLEDGE ARTICLE