1,4-dioxane is an unregulated industrial solvent often found in shampoos, bubble bath, cosmetic products -- and tap water. Across the U.S., 7 million people in 27 states are drinking water with elevated levels of the chemical that the Environmental Protection Agency classifies as a "likely carcinogen," according to a report published last week by the nonprofit Environmental Working Group (EWG).
Despite decades-long concerns about the chemical’s connection to cancer, liver and kidney damage, the EPA does not regulate 1,4-dioxane levels in drinking water. That leaves millions of people exposed, with no knowledge of the elevated cancer risk they could be creating for themselves.
According to the EWG, that's not the worst of it.
About 150 other unregulated chemicals are also found in trace amounts of the nation's drinking water. The nonprofit research organization contends that the EPA’s drinking water regulations are outdated.
“The EPA has not added a new chemical [to regulate] in 20 years, even as our environment and use of chemicals has changed dramatically,” says Nneka Leiba, director of healthy living science at EWG. “Around the country, almost all utilities are providing legal water. But they’re not providing completely safe and healthy water.”
According to the EPA, humans are at increased cancer risk from levels of 1,4-dioxane exceeding .35 parts per billion (ppb) in daily drinking water over the course of a lifetime. That's about one drop of 1,4-dioxane in three Olympic-sized swimming pools, according to the report, and the maximum amount of the chemical that should be allowed in drinking water, according to EWG.
Some consumers are getting about 17 times that amount of the chemical in their tap water.
“It’s striking how widespread this contamination is, and in how many different areas. It’s coming from groundwater and surface water,” says Tasha Stoiber, a senior scientist at EWG and an author of the report.
Most of the population consuming the chemical lives in three states: California, with 2.5 million people exposed, North Carolina (1.2 million) and New York (700,000). Many of the highest concentrations of 1,4-dioxane can be found in low-income and minority neighborhoods. All five of the highest-level contamination areas in California, for example, are Latino neighborhoods of Los Angeles.
View the interactive version of this map showing 1,4-dioxane exposure here. (Source: The Environmental Working Group)
In an email to Governing, the EPA wrote that 1,4-dioxane is one of the 10 chemicals it's reassessing under the updated Toxic Substances Control Act. But with Trump appointee Scott Pruitt at the helm of the EPA, EWG is doubtful the agency will start enforcing the .35 ppb standard.
The president’s nominee to the EPA’s Chemical Safety and Pollution Office, Michael Dourson, inspires even less hope for environmental advocates: He is head of the consulting firm TERA, which has argued against chemical regulations. He also personally released two review papers claiming people can safely be exposed to 1,000 times the limit of 1,4-dioxane suggested by the EPA.
That landscape in mind, regulation could likely be left up to the states. Some of them have already started.
In February, New York Gov. Andrew Cuomo formally called on the EPA to establish a legally enforceable standard for 1,4-dioxane, stressing that “this is a national issue.” But, he said, “New York State is prepared to [set a state standard] in the absence of federal leadership.”
California has a “notification level” of 1 ppb, at which point water utilities have to notify government agencies (but not necessarily the public). The policy, however, is purely advisory and not enforceable. New Hampshire also has a reporting limit for public water supplies. Colorado and New Jersey have enforceable groundwater standards, while North Carolina has an enforceable groundwater and surface water standard. And Maine and Massachusetts have drinking water guidelines.
“Some states do have regulations in place. We need more to adopt them, and those that have unenforceable guidelines should create actual standards,” says Stoiber. “We also need regulations for dischargers [of the chemical], to prevent contamination in the first place.”
There's evidence that this is starting to happen. Several states banned microbeads, which are often found in toothpaste and body wash and contribute to water pollution. Then in 2015, the federal government banned the distribution and sale of products containing them.
But it's easier said than done to devote resources to new and stricter regulations, say scientists and water pollution experts.
"I support the general position of the EWG that more could be done [to regulate contaminants in drinking water]," says Marc Edwards, an environmental engineering professor at Virginia Tech who helped uncover the Flint water crisis. But, he cautions, "we are in an era of declining discretionary resources, and cities and towns are struggling to meet existing regulations. Amongst the many worthy causes competing for an ever shrinking piece of the discretionary funding pie, this is another worthy cause."
Last week, EWG released an expansive database of the nation’s drinking water, and its findings are sobering. Using data from 2010 to 2015, EWG found 250 contaminants above health guidelines in the nation's drinking water. The EPA only regulates 100 chemicals.
Some of the most concerning unregulated contaminants include chromium-6, the chemical made infamous by the Erin Brockovich story, and MTBE, which is a gasoline additive. Ninety of the chemicals found by EWG have been linked with cancer and 60 with developmental harm to children. About 200 million Americans are currently being exposed to contaminants above EWG’s safety guidelines (though they can significantly reduce their exposure through the use of filters).
EWG health guidelines for drinking water come from data and research from the EPA and other government health organizations, most notably the California Office of Environmental Health Hazard Assessment, which sets strict standards for contaminants based only on public health outcomes with no regard for the cost of keeping contaminants out.
“What makes our analysis different is that we don’t believe legal necessarily means safe,” says Leiba. “We believe people deserve to know how contaminant levels in their water compare to health limits, as opposed to legal limits.”