Unfortunately, it is not uncommon for me to be shocked when I read the local newspaper each morning. This time, my interest was captured by the headline “When water turns poison in West Bengal…”
I wondered what could cause something as innocuous as water to turn into poison.
What surprised me most was that these reports of arsenic poisoning were not new. In fact, the first such cases of arsenic poisoning were reported in 1993 when Dr. K. C. Saha, a dermatologist from Calcutta, related the problem of skin lesions he observed to the high levels of arsenic in the drinking water.
Following this, Dr. Dipankar Chakraborti, Director of School of Environmental Studies, Jadavpur University, Calcutta, did extensive investigations and brought the issue to the attention of the world.
“Groundwater is found in aquifers which sit deep below the earth’s surface and are made up of porous rocks and gravel such as sandstone which saturate and hold the water, almost like a sponge. Arsenic can be present in these rocks, but how it can leach into groundwater is still not fully understood.”
Dr Chakraborti suggests that the ever increasing demands for groundwater are somehow affecting the geology of the groundwater aquifers, resulting in the release of the arsenic.
In addition to the contamination in West Bengal, a study in the medical journal Lancet in 2010 reported that 77 million people in Bangladesh had been exposed to toxic levels of arsenic through contaminated groundwater supplies. Also, earlier this year, a UNICEF survey uncovered that as many as 14,675 handpumps in Uttar Pradesh are contaminated.
As a result, scientists in Uttar Pradesh have “suggested setting up of ‘Permanent Arsenic Monitoring Stations’ so that a quality monitoring mechanism for testing the levels of arsenic in groundwater sources can be established and most critically contaminated areas could be identified”.
But, even if such monitoring can be put in place, there is a pressing need for India and Bangladesh to secure other sources of water supply, as they may no longer be able to use groundwater as extensively for irrigation and drinking water.
Perhaps rainwater harvesting and other such technologies will become more critical? What do you think?