A research published in a US scientific magazine Tuesday warned that underground water, the main source of water for the densely-populated Vietnam's Red River delta , is contaminated with deadly toxic chemicals.
Around 65 percent of tube wells studied in the area showed the water exceeds the WHO (World Health Organization) guidelines on arsenic, manganese, barium, selenium or a combination of these elements, the paper said on the US Proceedings of the National Academy of Sciences.
The study was conducted by foreign experts and scientists from Vietnamese institutes.
Excessive amounts of arsenic in water can cause skin, lung, bladder or kidney cancer as well as mental diseases while the same problem with manganese can severely affect the growth of children.
The pollution "poses a serious long-term health threat to about seven million people," the paper said, describing the situation as "particularly worrying" because groundwater is the main source of drinking water used in the delta, where 11 million out of 16.6 million residents do not have access to the public tap water and have to rely on other sources like ground water from private tube wells.
Arsenic pollution of groundwater, the research paper said, has been exacerbated by deep aquifer exploitation for more than a century.
It recommended the utilization of other sources of drinking water to avoid groundwater that contains high concentrations of arsenic and other contaminants in the long term.
It also suggested that residents and local authorities apply appropriate water treatment technologies to produce sustainable drinking water that meets safe water quality standards for both rural and urban populations.