||Arsenic was discovered in shallow tube wells of countries neighboring Nepal (West Bengal and Bangladesh) in the late 1970's.
Not until the late 1990's arsenic was discovered in groundwater of the Terai region of Nepal.
Arsenic in this region is a natural poison described by the World Health Organization as the worst natural disaster
in human history. Potentially over 450 million people in the Indo-Gangetic plain from the Indus river valley to
Bangladesh are drinking arsenic contaminated water.
The major source of arsenic in this region originates from arsenic sediments from the Himalayas, and igneous rocks in Bangladesh.