A newly identified chemical byproduct may be present in the drinking water of about a third of American homes, according to a study.
Scientists still do not know if this byproduct is dangerous.
But some are concerned that it may have toxic properties because of its similarities to other chemicals of concern.
About one-third of Americans receive water in their homes that contains a previously unidentified chemical byproduct, according to a new study. Some scientists are now concerned and investigating whether the chemical could be toxic.
The newly identified substance, called “chloronitramide anion,” is produced when water is treated with chloramine, a chemical formed by mixing chlorine and ammonia. Chloramine is often used to kill viruses and bacteria in municipal water treatment systems.
According to researchers, the existence of the byproduct was discovered about 40 years ago, but it was only identified now because analysis techniques have improved, which has finally allowed scientists to determine the structure of that substance.
It could take years to find out if chloronitramide anion is dangerous, since it has never been studied. The researchers published their findings Thursday in the journal Science, in part to stimulate research into its safety.
Scientists say they have no conclusive evidence to suggest the compound poses a danger, but it does have similarities to other chemicals of concern. They think it deserves scrutiny because it has been detected so frequently.
“It has similarities to other toxic molecules,” said David Wahman, one of the study’s authors and an environmental engineer at the Environmental Protection Agency. “We looked for it in 40 samples from 10 US chlorinated drinking water systems located in seven states, and it appeared in all of the samples.”
The “chloronitramide anion” is produced when chloramine breaks down over time. It is likely to be found in all drinking water treated by this method, he said.
The fact that a byproduct with unknown risks can be so ubiquitous and elude researchers for so long renews questions about the possible health effects of chemicals used to treat drinking water.
According to the study, about 113 million U.S. residents receive chloramine-treated water from their taps. This chemical product has been used for approximately a century to disinfect water. Nowadays, It is usually used to protect the “residue” of a systemthat is, water that remains in pipes for several days after leaving a water treatment plant.
Chloramine is increasingly preferred over chlorine because the latter also produces byproducts, some of which are associated with bladder cancer and are regulated by the Environmental Protection Agency (EPA).
David Reckhow, a research professor in civil and environmental engineering at the University of Massachusetts, Amherst, who was not involved in the study, said the finding was an important step. The ultimate goal, he said, is to know if the substance is dangerous; agreed that it probably is.
“It is a fairly small molecule and that is probably why it can enter biological systems and cells. And it is still a reactive molecule,” he said. “That’s the kind of thing that causes concern.”
The authors of the new study arrived at their results after figuring out how to formulate high concentrations of the chemical for laboratory testing, explained Julian Fairey, lead author and associate professor at the University of Arkansas.
“We don’t know the toxicity, but this study has allowed us to be able to do that work now,” said Fairey, who studies drinking water byproducts. “Now we can get down to the difficult task of trying to figure out what their toxicological relevance is to our water systems.”
He added that some previous studies have suggested a relationship between the consumption of disinfected water and the increased rates of certain types of cancer.
“We don’t know what this is about. We have no idea if this compound is in any way related to those results,” Fairey said. “But we have unexplained presence of certain types of cancer due to treated drinking water.”
However, There are still many years left to reach conclusions about the toxicity of the new substance. A possible regulation based on those results would take even longer.
“It’s a lot, it will probably (take) a decade of research once a funding source is found,” explained Alan Roberson, executive director of the Association of State Drinking Water Administrators.
Reckhow said that in the meantime, water companies should pay close attention to ongoing research and try to reduce people’s exposure.
“You do what you can to minimize it,” he said. “You make the best possible decision about toxicity and you work with incomplete information. That’s the world we live in, unfortunately.”
The EPA only regulates a handful of disinfectant byproducts, including several associated with the use of chlorine. Scientists say those regulations have pushed some water suppliers to increase their use of chloramine.
“This study really calls into question whether this disinfection process is safer from a health perspective,” said David Andrews, a scientist with the Environmental Working Group, an organization that advocates for greater control of chemicals.
Andrews added that there are hundreds of disinfection byproducts in water supply systems, but this one deserves to be examined.
“Many of these other contaminants appear at lower concentrations or less frequently,” he added.
According to Roberson, all drinking water treatment carries some health risk. This is a compromise: disinfection processes have largely eliminated waterborne diseases such as cholera and typhoid, but Research suggests that some byproducts are associated with risks of cancer and miscarriage.
“The reason why chloramine is added is that we want to kill bacteria and viruses,” he said.
Many water companies in the United States indicate on their websites whether they treat their water with chlorine or chloramine. According to Wahman, some research suggests that activated carbon filters, such as those used in home water purification devices or refrigerator filters, can remove disinfectant byproducts, but more research is needed.
