By IANS,
Sydney : Recycled water may not be safe for drinking, warn researchers who say such water is usually tested for only one kind of pathogen.
Flavia Huygens of the Queensland University of Technology in Australia is part of a team spear-heading a new and innovative water-testing technique that will check for all kinds of pathogens – in hours rather than days.
“Pathogens can be bacterial, viral or parasitic micro-organisms like cryptosporidium and giardia which can make people sick if enough is ingested,” Huygens said.
“However, the traditional method of testing is to look only for E. coli, an indicator of faecal contamination of the water supply. There is increasing evidence that questions the validity of relying solely on faecal indicator bacteria to assess health risks to humans, who either come into contact with contaminated water or ingest it,” she said.
“The (latest) testing method, based on polymerase chain reactions (PCR), allows us to magnify a pathogen’s DNA to determine exactly what it is and how much of it is there,” Huygens said.
“When you know how much of a pathogen is present, you can determine how risky the water is to drink or use and you can also then judge the best ways to disinfect it.
“Pathogenic micro-organisms have been identified as the main human health risks associated with the reuse of treated urban storm water, which is the runoff from paved and unpaved urban areas,” she added.
Huygens said current water testing methods can take several days to yield results, but the test developed at Queensland University of Technology takes under five hours to complete.