Water authorities in Abu Dhabi are working to rid drinking water of elevated levels of bromate, a chemical compound thought to cause cancer in humans, health experts told The Associated Press.
Bromate can appear when drinking water is produced from salty sources, and in the UAE and other desert countries, desalination of sea water is the dominant process for potable water.
Local and international officials stressed that the risk of cancer from bromate is probably very low - but not fully understood. No known cases of cancer in humans have been linked to bromate in water, experts said.
"We think that for the moment, there isn't an immediate threat to health," said Houssain Abouzaid, a Cairo-based water quality expert with the World Health Organisation familiar with the bromate problem in the Middle East.
"But something needs to be done. It's a long term problem, something that builds up over years," he said.
Tests of drinking water samples from the Abu Dhabi Water and Electricity Authority have shown bromate levels around ten times the WHO's recommended guidelines, according to Global Water Intelligence, an industry newsletter that reported the contamination in June.
Nick Carter, who heads Abu Dhabi's Regulation and Supervision Bureau, confirmed the findings and said the eight private plants that produce water have been taking steps to reduce bromate below the WHO threshold by today.
"It's not a big problem and within six months of finding the cause of it, we've solved it," Carter said. The bromate was introduced into the water after plants switched from treatment with volatile chlorine gas to using seawater-based chlorine, Carter said.
Some plants are returning to using chlorine gas until a better treatment can be found, he said. "It was such a dangerous gas to move around. There was a desire to move away from that," Carter said. "But in so doing, we created this bromate problem."
At the levels reported by the newsletter - around 100 parts per billion - bromate levels in water from the Abu Dhabi plants would surpass even WHO's previous guidelines of maximum levels of 25 parts per billion.
The organisation tightened that standard last year to ten parts per billion, Abouzaid said. In Britain last year, bottled water sold by Coca Cola that was found to contain around 25 parts of bromate per billion was recalled from stores.
Bromate has cropped up in drinking water elsewhere in the Gulf and around the world, said Joseph Cotruvo, a water quality consultant for the WHO and former director of drinking water standards and risk assessment in the US.
Natural bromide in seawater can be converted to bromate when technicians produce their own chlorine by electrolysing seawater and using it as a disinfectant, Cotruvo said.
Bromate also appears when saline water is treated with ozone, a disinfectant especially popular with producers of bottled water. Officials stressed that there was no need for the public to stop drinking tap water as long as water authorities were working to reduce bromate levels.
© 7Days 2006
