Many wells in Vietnam's Red River delta contaminated
More than a quarter of drinking wells in Vietnam's densely-populated Red River delta contain unsafe levels of arsenic that can cause cancer, neurological problems and hypertension, researchers warned on Tuesday.
In a paper published in the journal Proceedings of the National Academy of Sciences, they also said 44 percent of the wells in the delta carried levels of manganese that exceed World Health Organization guidelines.
"About 7 million people are at a considerable risk of chronic arsenic poisoning. This is particularly worrying because groundwater is the main source of drinking water throughout the delta," lead author Michael Berg wrote in an email to Reuters.
Arsenic contamination of groundwater occurs in many countries, like Argentina, Australia, Bangladesh, Chile, China, Hungary, India, Mexico, Peru, Thailand and the United States.
Manganese can disrupt the development of growing children.
Home to 16.6 million people, the delta straddles eight provinces and two municipalities, the capital Hanoi and Hai Phong port. Eleven million people have no access to the public water supply and are dependent on other sources, such as tubewells.
Experts have long known that groundwater in parts of southeast Asia contain unsafe levels of arsenic, a naturally occurring chemical, but their locations have never been clear.
Berg, a senior scientist at the Swiss Federal Institute of Aquatic Science and Technology, and colleagues collected samples from 512 private wells across the delta and analyzed them for arsenic, manganese and other toxins such as selenium and barium.
"Sixty-five percent of the groundwater wells in the Red River delta contain naturally occurring toxic elements, at levels which exceed the World Health Organization's (WHO) safety standards," Berg wrote.
"The most health threatening ... are arsenic, where 27 percent of the wells (are) above WHO guidelines and manganese, 44 percent."
Photo credit: http://www.discoveryindochina.com
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