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Ultraviolet radiation could become an environmentally friendly alternative to standard methods of disinfecting drinking water, researchers say.
"Theres the potential for a major paradigm shift in terms of whats appropriate disinfection technology for drinking water," said Mark Sobsey, professor of environmental microbiology at the University of North Carolina at Chapel Hill.
Research shows that UV radiation has the ability to stop single-celled parasites from multiplying in mammalian intestines by damaging their DNA.
"UV doesnt kill the cell right out. It just stops it from replicating," said Karl Linden, an environmental engineer at Duke University who is part of the technical working group advising the U.S. Environmental Protection Agency on UV disinfection.
The use of UV also can eliminate disinfection byproducts (DPBs). DBPs such as trihalomethane and haloacetic acid are formed from chlorine, added to drinking water to kill bacteria. However, prolonged exposure to DPBs may cause cancer, scientists say. Since UV also kills bacteria, its addition would allow for less chlorine and possibly eliminate the formation of DPBs.
The EPA is currently considering limits for cryptosporidium in drinking water as well as new lower limits for DBPs to be proposed next spring. UV radiation could become an approved technique to inactivate cryptosporidium.
Technology such as UV radiation could be added to existing water treatments, both filtered and unfiltered, to reduce the risk of disease, problems like DPBs, and perhaps avoid the need for massive filtration projects. "Theres still a lot of research being done. Theres a lot of excitement about using UV," said EPA advisor Linden.
(Source: Environment News Service)