According to recent research by scientists in Canada, two new nitrosamines were located in drinking water in a Canadian city -- and these nitrosamines can be 100 to 10,000 times more carcinogenic than the trihalomethanes (THMs) currently measured and treated in standard domestic water treatment facilities.
THMs -- a group of potentially carcinogenic drinking-water disinfection byproducts -- are a major health concern of the Environmental Protection Agency in the United States. Some studies have linked THMs to an increased risk of bladder cancer. Most water treatment facilities carefully monitor THM content in water pumped out to customer locations.
This Canadian finding suggests that a better methodology should be adopted to monitor the presence of nitrosamines in drinking water supplies. Current water treatment facilities often use a process called GC-MS to analyze water samples for nitrosamines and other compounds. The Canadian researchers used a far more sensitive testing process called LC/MS/MS to determine that the level of nitrosamines was much higher than they expected.
The Canadian study was published in the November 8 issue of Environmental Science & Technology. Researcher Xingfang Li from The University of Alberta and his research associates tracked a Canadian treatment plant and distribution system for the presence of nitrosamines for purposes of the study, and to determine nitrosamine levels throughout the process.
Li and his team detected four nitrosamines -- and all four were found in higher concentrations in the drinking water supplies they tested that what is considered safe by the American Chemical Society.
In addition to finding higher levels of the four nitrosamines, the measured levels actually increased in concentration as the water passed through the pipelines -- and the farther the water passed, the higher the concentrations of these nitrosamines occurred, according to Li and his team.
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