Drinking water from public utilities in 27 U.S. states, serving more than 7 million people, is contaminated with the industrial solvent 1,4-dioxane at levels that put people at increased risk of developing cancer, according to a new report from the Environmental Working Group (EWG).
The advocacy group compiled drinking water test data from nearly 50,000 public water utilities into an interactive map, showing the distribution of 1,4-dioxane in drinking water across all 50 states.
Areas with the greatest 1,4-dioxane contamination include the Cape Fear River basin in North Carolina, southeastern Los Angeles County in California, and New York’s Long Island. Water samples from those vicinities had levels of 1,4-dioxane four to 17 times as high as the level predicted by EPA to increase a person’s risk of developing cancer, the report finds.
“The extent of nationwide contamination is likely greater than what is shown in the map and database,” EWG points out. That’s because many small and medium-sized utilities do not test for 1,4-dioxane, and groundwater from private water wells, which is contaminated in some parts of the U.S. from leaking disposal sites, is exempt from testing.
EPA considers 1,4-dioxane a likely human carcinogen and is evaluating its safety under the revised Toxic Substances Control Act. The chemical is found as an impurity in some consumer products, such as cosmetics and household cleaners. Although 1,4-dioxane is no longer used as an ingredient in such products, it is often found in them as a by-product of the ethoxylation process. That process is used to manufacture surfactants.