Toxic Tuesdays

CHEJ highlights several toxic chemicals and the communities fighting to keep their citizens safe from harm.


1,4-dioxane is a clear liquid used in chemical manufacturing for industrial, consumer, and military purposes. During manufacturing or improper waste disposal 1,4-dioxane can be released into the environment. While it breaks down in air and doesn’t stick to soil, 1,4-dioxane is stable in water and can remain there for a long time. It can even accumulate in fish and plants that live in contaminated water. Eating these contaminated foods and drinking contaminated water are common ways people are exposed to 1,4-dioxane. Bathing in contaminated water can also cause 1,4-dioxane to evaporate into the air and be inhaled. Through its use in the manufacturing process, 1,4-dioxane often ends up being present in trace amounts in consumer products such as detergents, shampoos, and cosmetics. 1,4-dioxane present in these products can be absorbed through the skin.

Exposure to low levels of 1,4-dioxane can cause mild irritation to the eyes, nose, throat, or skin. Regardless of the route of exposure, high levels can cause kidney and liver damage as well as death. While there is little information about if 1,4-dioxane causes cancer in humans, animal studies have found that long-term exposure results in cancer, especially liver cancer. For this reason, the US Department of Health and Human Services believes that 1,4-dioxane likely causes cancer in humans.

In 2002, The Environmental Protection Agency (EPA) told water utilities across the country that 1,4-dioxane was being detected at many superfund sites. Subsequent testing in Arizona determined that it was present in groundwater pumped to the Tucson Airport Remediation Project (TARP) water treatment plant, but it is unclear how long this contamination had been going on. Sampling from wells around the treatment plant found a wide range of 1,4-dioxane levels, with some having concentrations 35 times the EPA’s health advisory level. It wasn’t until 2014 that a treatment facility removing 1,4-dioxane from the water became operational, meaning Tucson residents were at risk for at least 12 years. Community leaders have been fighting for answers: Who was exposed? For how long were they exposed? What will be done to identify and help people who are sick? CHEJ provided organizing and technical assistance to Environmental Justice Task Force in Tucson who organized around this issue. While Tucson Water says the TARP water treatment plant no longer has 1,4-dioxane contamination, in 2018 it was reported that a different class of dangerous chemicals, per- and polyfluoroalkyl substances (PFAS), were detected in water at this site. This illustrates that our current acceptance of the improper use, disposal, and remediation of harmful chemicals will continually present dangers to residents until people’s health is prioritized.

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