It’s unimaginable to be poisoned knowingly by your drinking water and food. But in parts of the world, this is the reality of daily life. Whether it is drinking from standing water or sharing a source with animals, more than one billion people worldwide have no clean water. Now imagine that you have clean water – or so you think – but it is invisibly killing you. This is the sobering truth in some places.
In the 1990s, arsenic contamination was discovered in the groundwater of the Bengal Delta in Eastern India and Bangladesh. More than 70 million people ingest arsenic with their drinking water and rice. Agricultural fields are irrigated with contaminated water. One estimate suggests that 6% of local people suffer from some degree of arsenic poisoning.
Arsenic is a highly toxic, naturally occurring element. Natural geological processes and industrial activities can contaminate groundwater so that it is unsuitable for drinking. In the Bengal Delta, geologically derived arsenic is the problem. A similar health challenge is faced in Ghana, where more than a century of gold-mining has caused serious pollution.
Arsenic poisoning causes nausea, abdominal pain, numbness, skin diseases, and organ damage. In addition, various forms of cancer have been linked to arsenic. Chronic exposure can occur over years before any symptoms appear. The only treatment response is to limit arsenic intake immediately.
Since the symptoms are serious, why wasn’t this problem obvious earlier? As it turns out, groundwater has been exploited only recently in the region, encouraged by a high water table and rapid replenishing by monsoon rains. Goverment agencies and other groups have promoted groundwater as a important resource. Simple hand pumps are sufficient to extract water, making tube wells practical. Groundwater has solved a number of important problems – infant mortality has dropped with fewer diarrheal diseases and irrigation for agriculture.
Researchers from Queen’s University in Belfast are developing a method to treat groundwater. It involves injecting air into the groundwater – to circulate with remaining water. The treatment has several positive effects. At higher oxygen levels, less soil-bound arsenic will dissolve into water. In addition, with more dissolved oxygen, organisms in the soil use available arsenic and remove it from the water.
The hope is that affordable decontamination will supply safe drinking water and irrigation. Many village councils and local financial institutions have been involved in the initial project, offering onsite monitoring and support. A plant has been built in Kasimpore, near Kolkata. The technicians are local residents, ensuring a self-managed and sustainable venture.
The World Bank has also granted $200,000 to TiPOT, the group coordinating the effort, to finance an additional six plants. In recognition of the project’s potential impact, the British Council recently awarded funds for education and training in water management. If the initial plants are successful, the innovation may create an arsenic-free future.
