Skip to main content
An official website of the United States government

Contaminants in Drinking Water

Over the years, DCEG research on the association between contaminants in drinking water and cancer has made a significant impact in the following areas:

A DCEG study found no evidence that fluoride in drinking water poses an elevated risk of cancer, as had been suggested by some previous reports. This finding was confirmed by expert panels convened in the United States, the United Kingdom, and other countries, providing further confidence in the safety of water fluoridation (Hoover et al., 1976).

Water suppliers often add disinfectants to drinking water to eliminate disease-causing organisms, or pathogens. These disinfectants react with naturally-occurring organic material in the water to form disinfection byproducts, which may pose health risks. The Environmental Protection Agency lowered the allowable maximum allowable levels for two groups of disinfection byproducts, trihalomethanes and haloacetic acids, in drinking water, after a DCEG study linked them to elevated bladder cancer risk (Cantor et al., 1987). 

DCEG research on dietary and drinking water nitrate contributed to the International Agency for Research on Cancer monograph review (2010) of ingested nitrate and nitrite and cyanobacterial peptides (Ward et al., 1996, 2000, 2007; DeRoos et al., 2003; Coss et al., 2004). Ingested nitrate and nitrite was determined to be possibly carcinogenic to humans (2A).

Contaminants in Drinking Water: Full list of article citations

Learn about our current research on contaminants in drinking water