Arsenic is naturally occurring in pyrite bedrock underlying much of West Bengal. The poisoning began to occur as millions of kiloliters of water was being pumped out from deep within underground reservoirs. As a result the water level dropped and exposed the arsenic-bearing pyrite to air leading to oxidisation, a reaction which flushed arsenic into the remaining water.

Arsenic is a slow killer that accumulates in the body resulting in nails rotting, dark spots, bleeding sores, swelling, large warts and a form of gangrene. It is carcinogen increasing the risk of skin cancer and tumors of the bladder, kidney, liver and lungs.

Villagers in Jampukkur, first noticed something was wrong in the 1970’s when dark spots spread across their bodies. They finally learned they were drinking arsenic contaminated water in 1993 when official tests showed 95% of the village wells were contaminated.