Silverdocs film festival addresses pollution in Cambodia

Tuesday, June 22, 2010
Excerpt from The Washington Post
POLLUTION

Troubled water, near and far

Silverdocs

The annual Silverdocs documentary film festival runs through June 27 in Silver Spring. This year's lineup of 102 films from 54 countries includes a few films with science themes, such as "Born Sweet," a heartbreaker about Vinh, a Cambodian boy with arsenic poisoning. In his rural village, tainted drinking water has given someone in almost every family arsenic poisoning, which causes black spots on the skin, coughing, diarrhea and vomiting. Vinh's father and grandfather are also afflicted. The boy dreams of becoming a karaoke star but grapples with what he sees as his destiny: "In this world, some people are salty, some people are sweet," he says in a voice-over. "The salty are strong, the sweet are sickly." This 28-minute film plays with a group of three other shorts Tuesday at noon at the AFI Silver Theatre and also on June 23. See http://www.silverdocs.com for ticket information.

Mass arsenic poisoning mystery solved

Monday, 16 November 2009
AFP/Reuters

Researchers have finally worked out what led to the widespread release of arsenic into drinking water in rural Bangladesh, affecting millions of people.

Dubbed 'the worst mass poisoning in history', the incident has puzzled scientists for decades.

Now a team publishing in Nature Geoscience say that tens of thousands of man-made ponds are to blame.

Arsenic is a naturally occurring chemical poisonous to humans and is known to cause skin lesions and cancers of the bladder, kidney, lung and skin.

An estimated two million people in Bangladesh have been poisoned by arsenic in water drawn from millions of low-tech "tube wells" scattered across the country.

Ironically, the wells were dug with the help of international aid agencies to protect villages from unclean and disease-ridden surface water.

Poisoning symptoms include violent stomach pains and vomiting, diarrhoea, convulsions and cramps. A large dose can kill outright, while chronic ingestion of small doses has been linked to a large range of cancers.

Health experts suspect the toxic, metal-like element has caused many deaths as well.

Carbon source

Arsenic is widely distributed throughout the earth's crust and is introduced into water through the dissolution of minerals and ores.

It is known that organic carbon triggers the release of arsenic from sediments into groundwater, but until now the source of this carbon has been unclear.

US environmental engineer, Dr Charles Harvey from the Massachusetts Institute of Technology, and colleagues have now found that man-made ponds are a key source of organic carbon.

They used chemical tests and models to study the interaction between the ponds, groundwater, aquifers and sediments in a 15.5 square-kilometre area of the Munshiganj district - a typical rice-growing area of Bangladesh.

The researchers used natural tracers and a 3-D computer model to track water from rice fields and ponds, and tested the capacity of organic carbon in both settings to free up arsenic from soil and sediments.

"We saw that water with high arsenic content originates from the human-built ponds, and water with lower arsenic content originates from the rice fields," says co-author Dr Rebecca Neumann.

Groundwater pumping for agriculture carries the organic carbon underground, where it triggers the arsenic release, say the researchers.

'A breakthough'

Professor Scott Fendorf, of Stanford University who studies arsenic content in soils and sediments along the Mekong River in Cambodia, says the new study is clearly a breakthrough.

"It shows that human modifications are impacting the arsenic content in the groundwater," he says. "The ponds ... are having a negative impact on the release of arsenic."

The authors of the new study warn against the building of artificial ponds above existing tube wells.

"The development of artificial ponds above wells should be avoided if it is possible, and drinking-water wells should not be placed downstream of recharge from existing ponds, wetlands, rivers or other permanently saturated water bodies potentially elevated in organic carbon," they say.

They plan to dig such wells in different region to see whether it leads to improved health for villages.

Arsenic contamination of ground water has been found in other countries, including Argentina, Chile, China, India, Mexico, Taiwan, Thailand and the United States, and is a global problem.

But Bangladesh's plight is unprecedented and some experts have described it as the largest mass poisoning of a population in history.

According to the World Health Organization, arsenic contaminated water directly affects the health of 35 million people in Bangladesh, which has a total population of 130 million.

Tragically, millions of people continue to knowingly poison themselves for lack of an alternative source of water.

Rice from arsenic-laced water regions in Bengal, Cambodia and VN, could be poisoned

Bengal rice could be poisoned: British researchers

30/10/2007
Hindustan Times (India)

People living in West Bengal could be exposing themselves to potentially cancer-causing arsenic by eating locally grown rice, British researchers said on Tuesday.

However, the researchers from the University of Manchester said that modifying the way rice is cooked could be a way of reducing arsenic exposure.

They told an international meeting of environmental experts at Manchester that the presence of naturally occurring petroleum in West Bengal and Cambodia could be responsible for the release of arsenic into water used for drinking.

They presented their findings at a workshop on arsenic in groundwater in Southeast Asia at Manchester University.

"Arsenic in ground waters in Bangladesh and West Bengal constitutes a major hazard to human health. Several tens of millions of people are impacted by using these waters for drinking, cooking and irrigation," David Polya from the university said.

"An environmental health disaster is unfolding in these areas. Tens of millions of people in many districts are drinking ground water with arsenic concentrations far above acceptable levels.

"Thousands of people have already been diagnosed with poisoning symptoms, even though much of the at-risk population has not yet been assessed for arsenic-related health problems," he added.

Researchers at the university and the Swiss Federal Institute of Aquatic Science and Technology have been among the first to identify similar hazards in Cambodia and Vietnam.

Although the two-day meeting is focussed on those two countries, the discussions also have relevance to other parts of the world.

"We have the chance and the responsibility here to encourage mitigation largely before such health impacts take place," Polya added.

The meeting was told by a leading development worker that thousands of people in Cambodia will die of cancer and other arsenic related health issues if more action is not taken soon.

Mickey Sampson of Resource Development International Cambodia - a NGO that runs a range of projects - said that more than 1,500 Cambodian villages are at high risk from arsenic in ground water.

In a village called Preak Russey, 264 people are suffering from debilitating levels of arsenicosis, he said, adding that in such villages most of the tube wells have arsenic levels 200 times the World Health Organisation (WHO) guideline - ironically, many of them sunk by NGOs.

He said arsenicosis symptoms have been found in villagers who have been drinking drawn from tube wells for only three years.

Children are at a higher risk than adults, he warned.