Current knowledge on the distribution of arsenic in groundwater in five states of India

Abstract

Testing of groundwater used for drinking for arsenic has been undertaken more widely by state governments in several states of India in recent years with the support of UNICEF. Available data for five states are collated in this paper and this provides the most up-to-date picture of areas known to be affected by arsenic in groundwater in the Indian portion of the Ganges-Brahmaputra river basin. In West Bengal, water from 132,262 government installed handpumps in 8 districts has been tested and overall 25.5% of samples were found to contain arsenic at concentrations greater than 50 μ gL⁻¹ and 57.9% at concentrations greater than 10 μ gL⁻¹. On the banks of the Brahmaputra in Assam, to date, samples from 5,729 government handpump sources in 22 districts have been tested for arsenic. Overall, samples from 6.3% of sources were found to contain arsenic at concentrations greater than 50 μ gL⁻¹ and 26.1% at concentrations greater than 10 μ gL⁻¹. In Bihar, on the River Ganges upstream of West Bengal, 66,623 sources from 11 districts have been tested and water samples from 10.8% of sources were found to contain arsenic at concentrations greater than 50 μ gL⁻¹ and 28.9% at concentrations greater than 10 μ gL⁻¹. Upstream of Bihar in Uttar Pradesh, home of the Taj Mahal, to date water samples from 20,126 government-installed handpump sources have been tested. As a result 2.4% of the samples tested were found to contain arsenic at concentrations greater than 50 μ gL⁻¹ and 21.5% at concentrations greater than 10 μ gL⁻¹. Finally in one district of Jharkhand, lying on the Ganges alluvial plain between Bihar and West Bengal, 9,007 sources have been tested and water samples from 3.7% of sources were found to contain arsenic at concentrations greater than 50 μ gL⁻¹ and 7.5% at concentrations greater than 10 μ gL⁻¹. State governments have adopted different sampling strategies and these are described in this paper. Testing is ongoing in several states and the complete picture is yet to emerge in some areas.

Keywords:

• Arsenic
• arsenicosis
• groundwater
• drinking water
• West Bengal
• Assam
• Bihar
• Uttar Pradesh
• Jharkhand
• India

Acknowledgments

The field testers, laboratory chemists, NGO workers, University researchers, district and block officials and village volunteers who carried out the field and laboratory analysis to generate the data summarized in this paper, and are too numerous to name individually, are thanked for their conscientious and untiring work. Three anonymous reviewers are thanked for their excellent comments on the draft manuscript which greatly improved the final version. Paresh Patel of CyberSwift in Kolkata is thanked for providing GIS block basemaps for Figure 1 and Figure 5. The financial assistance of UK Department for International Development and the Swedish International Development Cooperation Agency to UNICEF India Child's Environment Programme is gratefully acknowledged.

The opinions expressed in this paper are those of the authors and do not necessarily reflect the views of their institutions of employment.

Notes

*Screening indicates that a subset of all sources only were tested, blanket indicates that all sources in the area in question were tested. Testing is ongoing in Uttar Pradesh, Bihar and Jharkhand and widespread testing will shortly begin in Assam.