Scientists have identified a new chemical byproduct in tap water consumed by millions of Americans, solving a decades-long mystery. This compound, formed during water purification with chloramine, raises health concerns for roughly 113 million people and warrants further investigation into its potential toxicity.
Chloramine is a disinfectant created by combining chlorine with ammonia. It is preferred over chlorine in many water treatment systems due to its greater stability, which results in lower levels of disinfectant byproducts compared to chlorine.
Although researchers first noted the unidentified chemical byproduct in tap water treated with chloramine nearly 40 years ago, its exact details were not known. In a recent study published in Science, scientists used advanced analytical methods to uncover its structure, which is now officially named chloronitramide anion.
The researchers detected chloronitramide anion in all 40 samples taken from 10 drinking water systems located in seven states. It was not seen in ultrapure water, or drinking water treated without chlorine-based disinfectants.
“It’s well recognized that when we disinfect drinking water, there is some toxicity that’s created. Chronic toxicity, really. A certain number of people may get cancer from drinking water over several decades. But we haven’t identified what chemicals are driving that toxicity. A major goal of our work is to identify these chemicals and the reaction pathways through which they form,” Julian Fairey, first co-author on the paper said in a news release.
The study represents a significant breakthrough, as it successfully identified chloronitramide anion and determined its structure.
“It’s a very stable chemical with a low molecular weight. It’s a very difficult chemical to find. The hardest part was identifying it and proving it was the structure we were saying it was,” Fairey noted.
Although the toxicity of chloronitramide anion remains uncertain, researchers have raised concerns due to its widespread presence and structural similarities to other toxic compounds. They stress the need for further investigation by academics and regulatory agencies, such as the U.S. Environmental Protection Agency.
“Even if it is not toxic, finding it can help us understand the pathways for how other compounds are formed, including toxins. If we know how something is formed, we can potentially control it,” Fairey added.
