Study of arsenic (As) mobilization in the Ganga Alluvial Plain using neutron activation analysis

In northern part of Indian sub-continent, As related environmental and health issues receive attention from all over the world. Forty-eight sediment samples were collected from the Ganga Alluvial Plain (GAP) and its weathering products (from the Gomati River) for the study of As distribution and mobilization. These sediment samples were analyzed by Instrumental Neutron Activation Analysis (INAA) method using Cirus Research Reactor of Bhabha Atomic Research Centre, Mumbai. Average As concentrations in the GAP sediments (10.44 mg kg-1), the Gomati River bed sediments (1.36 mg kg-1) and the Gomati River suspended sediments (5.30 mg kg-1) were reported. Significant decrease of As content from the alluvial sediments to the river sediments is a clear indication of its mobilization by chemical weathering processes of mineral biotite. Present study demonstrates the importance of INAA for quantification and mobilization of As and improves our understanding related to As related environmental issues in northern India and elsewhere. (author)