Safe to drink? A new study raises concerns about drinking water disinfected with chloramines.
disinfecting drinking with chloramines, a mixture of chlorine and ammonia, which is used to treat about a third of drinking water in the United States may have the unintended consequence of producing toxins, a new study suggests.
Although chlorine remains the most widely used disinfectant in the United States, the popularity of chloramine has increased, partly because of the perception that it is safer because it is less byproducts. Chlorine creates potentially harmful byproducts when it reacts with other compounds normally present in drinking water systems. Most scientists blame byproducts of disinfection of a link between the disinfection of water and risk of bladder cancer or miscarriages in humans, but they do not know where about 00 sub products are the culprits. Much less by-products result from chloramines and other chlorine alternatives currently in use, it remains concerned because the handle by-products regulated by the Environmental Protection Agency (EPA) are the most common, but not necessarily the most toxic.
When EPA 02 survey of drinking water revealed another potentially dangerous type of compound - supposedly iodinated byproducts - in drinking water from a Texas utility using exclusively chloramine, the discovery came "a total surprise," said Susan Richardson, an EPA chemist who led the investigation. Now she, toxicologist Michael Plewa of the University of Illinois, Urbana-Champaign, and colleagues identified five iodinated byproducts. one of them, iodoacetic acid (IA), is the most toxic to mammalian cells of any by-product of disinfection ever tested, they reported online 17 in August Environmental Science & Technology . the results suggest that the transition from chlorine to chloramine can be bad for people's health, said Plewa.
But others are not so sure. Even if some of iodinated byproducts are much more toxic than those currently regulated, they are probably too rare to harm people, said EPA engineer Stig Regli environment in Washington, DC Chemist Stuart Krasner of the Metropolitan Water District of Southern California la Verne adds that the scarcity of iodinated byproducts also means they are unlikely to be responsible for the risk of bladder cancer.
Plewa counters that the amounts of iodinated byproducts in US drinking water are virtually unknown, making it impossible to assess the risk they pose. Richardson is currently working on a project to trace those levels.
Related Sites
EPA Sheet disinfection byproducts
The 02 EPA study on disinfection by-products
Michael Plewa home page
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