overview
A newly identified chemical byproduct may be present in the drinking water of about one-third of U.S. homes, a study has found. Scientists don’t yet know whether the byproducts are dangerous. However, some are concerned that it may have toxic properties due to its similarities with other chemicals. Concerns.
About a third of U.S. residents were consuming tap water containing previously unidentified chemical byproducts, a new study finds. Some scientists are now concerned that the chemical may be toxic and are actively investigating it.
The newly identified substance, named “chloronitramide anion,” is produced when water is treated with chloramine, a chemical formed by mixing chlorine and ammonia. Chloramines are often used in municipal water treatment systems to kill viruses and bacteria.
The existence of this byproduct was discovered about 40 years ago, researchers said, but improvements in analytical techniques that finally allowed scientists to determine the structure of the chemical made it difficult to identify. It has only now been identified.
It could take years to figure out whether the chlornitramide anion is dangerous, but it has never been studied. The researchers reported their findings Thursday in the journal Science in an effort to spur research to address safety concerns.
Scientists said there is no solid evidence to suggest the compound is dangerous, but it does have similarities to other chemicals of concern. They believe it deserves scrutiny because it has been detected so widely.
“There are similarities with other toxic molecules,” said David Warman, one of the study authors and a research environmental engineer at the Environmental Protection Agency. “We looked for this substance in 40 samples from 10 chlorinated drinking water systems in seven states in the United States. We found it in every sample.”
The chlornitramide anion is formed when chloramine breaks down over time. It is likely to be detected in all drinking water treated in this way, he said.
The fact that byproducts with unknown risks are so ubiquitous that they may have eluded researchers for a long time raises questions about the potential health effects of chemicals used to treat tap water. I am renewing my doubts.
Studies show that approximately 113 million U.S. residents receive chloramine-treated water from their taps. This chemical has been used to disinfect water for about a century. It is now commonly used to protect the system’s “residual water” – water that remains in the pipes for several days after leaving the water treatment plant.
Chloramines are increasingly being preferred over chlorine because chloramines also produce byproducts, some of which have been linked to bladder cancer and are regulated by the EPA.
David Reckhow, research professor of civil and environmental engineering at the University of Massachusetts Amherst, who was not involved in the study, said the discovery is an important step. The ultimate goal is to understand whether the substance is dangerous, he said. He agreed that it was probably toxic.
“This is a fairly small molecule, and perhaps that’s why it has the potential to enter biological systems and cells. And it’s still a reactive molecule,” he said. “That’s what you’re worried about.”
The authors of the new study arrived at this result after devising a way to formulate high concentrations of chemicals for clinical testing, said lead author Julian Fairley, an associate professor at the University of Arkansas.
“We don’t know the toxicity, but this study allows us to do that,” said Fairey, who studies drinking water byproducts. “Now we can begin the hard work of elucidating its toxicological relevance in our water systems.”
He added that some past studies have suggested a link between drinking disinfected water and increased incidence of certain cancers.
“We don’t know what’s causing these. We don’t know if this compound is somehow related to those outcomes,” Fairley said. “However, there have been unexplained incidents of certain types of cancer developing from treated drinking water.”
But a conclusion on whether the newly identified substances are toxic will likely be years away. Potential regulations based on these final findings will take more time.
“That’s a lot of money,” said Alan Roberson, executive director of the State Drinking Water Administrators Association. “Once we find a funding source, it’s probably going to take a 10-year study.”
In the meantime, Reckhow said water utilities should pay close attention to ongoing research and work to reduce people’s exposure.
“We do everything we can to minimize it,” he said. “You’re making the best decisions you can about toxicity and doing it based on incomplete information. Unfortunately, that’s the world we live in.”
EPA only regulates a small number of disinfectant byproducts, including some byproducts associated with the use of chlorine. Scientists said these regulations are prompting some water utilities to increase their use of chloramines.
“This study really calls into question whether this disinfection process is safer from a health standpoint,” said David, a senior scientist at the Environmental Working Group, an advocacy group that promotes greater scrutiny of chemicals. Andrews said.
He added that hundreds of disinfection byproducts have been found in water systems, which deserve scrutiny.
“Many of the other pollutants occur at lower concentrations or occur less frequently,” Andrews said.
Roberson said drinking water treatment comes with some health risks. This is a trade-off. Disinfection processes have nearly eradicated waterborne diseases like cholera and typhoid fever, but research suggests some byproducts are associated with risks of cancer and miscarriage.
“The reason we add chloramines is to kill bacteria and viruses, and there’s really a risk-risk tradeoff,” he says.
Many U.S. water utilities disclose on their websites whether the water they supply is treated with chlorine or chloramines. Wurman said some research suggests that activated carbon filters, such as those used in household water purifiers and refrigerator filters, can remove disinfectant byproducts, but more research is needed.
