VietNamNet Bridge – Dr. Pham Hung Viet and his coworkers from the Hanoi National University have published many research works about soil pollution, sediment and underground water geochemistry in international publications over the last 15 years.

The work includes research on arsenic pollution, conducted after Viet read a report from the 1998 British Geological Survey that analysed an epidemic of arsenic poisoning in 61 of 64 provinces in Bangladesh. That survey finding ignited the world’s interest as arsenic-containing underground water was found in 70 countries, placing more than 130 million people at risk of contamination.

As Vietnam and Bangladesh have similar geological conditions (they both are located in the basin of major rivers originating from the Himalayas), Viet thought the underground water in Vietnam might also be contaminated with arsenic.

Viet and his coworkers began to work with EAWAG, the Swiss science and environmental research institute to examine water in the Red River Delta and Hanoi.

In 2001, the research on pollution of underground water in Vietnam and the threat to human health was published in the Environmental Science and Technology, a prestigious science journal.

The article pointed out that arsenic concentration in the inner city and suburban areas of Hanoi was higher than the permitted level, and warned that people using water from self-drilled wells (which have an arsenic concentration higher than 10 micrograms per liter) could suffer from chronic arsenic infection.

Over the last 10 years, the findings have been quoted more than 600 times in different documents and papers.

However, many questions about arsenic remain unanswered, including how to predict the possibility of arsenic contamination, how arsenic is released, how arsenic is transported between aquifers, and the role of microorganisms in the release of arsenic.

The research team headed by Dr. Viet tried to discover the relation between underground water exploitation and arsenic contamination.

The sediment and water samples taken from the Van Phuc fishing village were analyzed at some of the most sophisticated laboratories in the world, including ETH Zurich and Lamont-Doherty Earth Observatory at Columbia University in the US.

The scientists discovered that water exploitation activities had caused the contamination. They also found that arsenic contamination occurred in some places but not in others, depending on the geochemical composition of underground water sediment.

Dr. Viet said this was the first time that scientists were able to show how a clean water aquifer becomes contaminated with arsenic and how this depends on the capability of the underground water suction pump.

“Arsenic contamination in Hanoi has been proceeding more slowly than was feared. However, if city residents increase their underground water exploitation, the problem will become much more serious,” Viet said.

Tia Sang