University of Illinois geneticist Michael Plewa said that disinfection by-products (DBPs) in water are the unintended consequence of water purification. "The reason that you and I can go to a drinking fountain and not be fearful of getting cholera is because we disinfect water in the United States," he said. "But the process of disinfecting water with chlorine and chloramines and other types of disinfectants generates a class of compounds in the water that are called disinfection by-products. The disinfectant reacts with the organic material in the water and generates hundreds of different compounds. Some of these are toxic, some can cause birth defects, some are genotoxic, which damage DNA, and some we know are also carcinogenic."
The first discovery of the University of Illinois research team involved water with naturally high bromine and iodine in it, produced primarily from sea water or underground aquifers most likely linked to ancient sea beds in the past. When this type of water was disinfected with chemicals, DBPs were produced that had iodine atoms attached -- creating a gene harming toxin.
The second discovery revealed a danger from nitrogen-containing DBPs. "Disinfectant by-products that have a nitrogen atom incorporated into the structure are far more toxic and genotoxic, and some even carcinogenic, than those DBPs that don't have nitrogen. And there are no nitrogen-containing DBPs that are currently regulated," Dr. Plewa said in the media statement.
Our skin is not waterproof; it absorbs water. That's why it becomes wrinkly like a prune after we sit in the bath or swimming pool too long. Our skin doesn't absorb that much water, but absorption does occur.
Then what about what the environment is putting in your water without the help of what we use to "clean" the water?
Bokor, the Idaho Department of Environ-mental Quality's regional drinking water protection coordinator, and a number of other water officials and companies set themselves up inthe KMVT Community Room on Saturday for a water-quality fair, featuring free tests for nitrate levels in private wells. Such wells aren't regulated by the state and testing is the owner's responsibility, he said. But it's something that owners should do, given the risks involved.
Twin Falls County now hosts the No. 1 nitrate priority area in the state for its level of contamination. And in a report released March 27, the U.S. Geological Survey announced that more than 20 percent of private domestic wells sampled nationwide by the agency contain at least one contaminant at levels that prompt possible health concerns. The data came from around 2,100 private wells tested between 1991 and 2004, including some in the Magic Valley.
The specific contaminants varied by region and type of rock, but included nitrate, radon and arsenic - the last one specifically noted as existing in Idaho's basalt-rock aquifers. The agency estimated that about 43 million people, 15 percent of the population, rely on drinking water from private wells.
Of all the disinfectants, the chemistry and toxicity of the reaction by-products of chlorine have been the most extensively studied.
Chloramine generally produces by-products similar to those observed with chlorine but at much lower concentrations. The use of chloramine as a disinfectant has increased in recent years because of limited formation of THMs, however, little is known about the nature of other by-products.
The main disinfection by-products of chlorine dioxide are chloride, chlorate and chlorite. Chlorine dioxide is more effective towards inactivation of Giardia cysts than free chlorine, but less effective towards rotavirus and E. coli. Unlike chlorine, the disinfection efficiency of chlorine dioxide is independent of pH and the presence of ammonia.
Ozone is the most efficient disinfectant for all types of microorganisms. Disadvantages include lack of disinfectant residual, biological regrowth problems in distribution systems, high cost, and limited information on the nature and toxicity of its by-products.
Something to keep in mind is the risk of death from pathogens is at least 100 to 1000 times greater than the risk of cancer from disinfection by-products.
So why does it seem very active swimmers are more likely to have bladder cancer? I am sure all this will be research and studied in the near future.
Sources: University of Illinois at Urbana-Champaign (2009, April 7). What's In Your Water? Disinfectants Create Toxic By-products In Drinking Water And Public Swimming Pools.
Regli S., Berger P., Macler B., Haas C. (1993). Proposed decision tree for management of risks in drinking-water: consideration for health and socioeconomic factors. In: Safety of water disinfection: balancing chemical and microbial risks. Craun G.F. ed. ILSI Press, Washington, D.C.
Thank you for acknowledging this issue. Contaminated water really is an overlooked problem all around the world. If anyone out there would like to DO SOMETHING about this tragic problem, please visit International Action's website, haitiwater.org. My making even a small donation you can help International Action give Haitians access to clean water. Thanks to the inexpensive chlorinators intalled by International Action, people of all ages are relieved of the deadly health effects of contaminated water like chronic diarrhea, typhoid, and malaria. Help us help Haiti at haitiwater.org. -Tamara, International Action Intern
Thank you for acknowledging this issue. Contaminated water really is an overlooked problem all around the world. If anyone out there would like to DO SOMETHING about this tragic problem, please visit International Action's website, haitiwater.org. My making even a small donation you can help International Action give Haitians access to clean water. Thanks to the inexpensive chlorinators intalled by International Action, people of all ages are relieved of the deadly health effects of contaminated water like chronic diarrhea, typhoid, and malaria. Help us help Haiti at haitiwater.org.
-Tamara, International Action Intern