Risk Assessment of Arsenic Toxicity Through Groundwater-Soil-Rice System in Maldah District, Bengal Delta Basin, India

Arsenic (As), a toxic trace element, is of great environmental concern due to its presence in soil, water, plant, animal and human continuum. Its high toxicity and increased appearance in the biosphere have triggered public concern. The present study measured As concentrations in soil, groundwater and rice plant samples of five selected blocks of Maldah district, West Bengal, India. Soil, irrigation water and rice plant samples were collected from the fields of the selected study areas. The results revealed the presence of As in higher concentrations than the maximum permissible limit of As in irrigation water (0.1 mg L-1 by FAO, 2010) in groundwater of Manikchak (0.553 +0.17 mg L-1), Kaliachak III (0.528 +/- 0.20 mg L-1), and Kaliachak II (0.449 + 0.15 mg L-1), Kaliachak I (0.207 + 0.19 mg L-1). The soil As was also found higher in those four blocks. The As content in rice grain of the study area was positively correlated (r = 0.896**, p < 0.001) with As content in irrigation water. The data of consumption of rice per day in the survey were used for the measurement of average daily intake, Hazard quotient (HQ) and Incremental Life time Cancer Risk. Kaliachak III, Manikchak and Kaliachak II showed HQ greater than 1, indicating the possibility of non-carcinogenic health hazard due to As exposure to the local residents. The study emphasized the severity of As problem in remote areas of West Bengal where people consume As tainted rice due to lack of awareness about the As associated health issues. [GRAPHICS] .