Arsenic Contaminated Irrigation Water and Its Impact on Food Chain

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 has triggered public and political concern. Out of the 20 countries (covering Argentina, Chile, Finland, Hungary, Mexico, Nepal, Taiwan, Bangladesh, India and others) in different parts of the globe where groundwater arsenic contamination and human suffering there from have been reported so far, the magnitude is considered to be the highest in Bangladesh, followed by West Bengal, India (Sanyal et al. 2012, 2015; Sanyal 2016a, b). The scale of the problem is grave and unprecedented, exposing millions of people in the Bengal delta basin to risk. The widespread arsenic contamination in groundwater in different parts of West Bengal, located primarily in five districts adjoining the river Bhagirathi, as well as the contiguous districts in Bangladesh, is of great concern. Even beyond the Bengal delta basin, the widespread arsenic contamination in groundwater above the permissible limit (50 μg/L; WHO 2001; see below) has also been detected in several places in the country (Table 13.1, Fig. 13.1), for instance at Chandigarh (1976), Nepal (2001), Bihar (2002), Uttar Pradesh (2003), Jharkhand (2003–2004) (Sanyal et al. 2015; Sanyal 2016a, b), Chhattisgarh and Punjab (2006–2007).