Groundwater Quality Indexing for Drinking Purpose from Arsenic Prone Areas, West Bengal A Health Risk Assessment Study

Abstract

Arsenic (As) has been categorized as group I human carcinogen (ATSDR 2014) among the toxic substances. The United States Agency for Toxic Substances and Disease Registry (ATSDR 2007) has marked arsenic under group I category, depending on its level of health hazard and toxicity. Groundwater arsenic-contamination is considered as one of the most serious emerging problem in today’s world (Mohana et al. 2020, Landrigan et al. 2018). In different regions of the world, considering past decades, groundwater arsenic-contamination is one of the major community and environmental health concern (Sharma et al. 2017, Tabassum et al. 2019). The GMB plain is undertaken as the menace due to arsenic-contamination in groundwater (Chakraborti et al. 2018, Das et al. 2020, Shakoor et al. 2016). West Bengal under GMB plain (world’s largest delta) is rich with arsenic in soil (Chakraborti et al. 2013, Chowdhury et al. 2018a). In West Bengal, Gaighata and Deganga are the two well-known arsenic affected blocks in North 24 Parganas district (Chowdhury et al. 2018a, b, Joardar et al. 202la, b, Roychowdhury 2010). The use of groundwater is increasing due to rapid increase of population. Groundwater, the most abundant natural resource, is mainly used for both domestic and irrigational purposes (Chakraborti et al. 2011). Arsenic in groundwater varies depending on several factors like depth of the tube-well, source and geographical location (Rabanni et al. 2017, Shahid et al. 2017). In Bengal delta, the inhabitants residing in arsenic-contaminated areas are using groundwater from both the sources like domestic shallow tube-well (STW) and deep tube-well (DTW) installed by the local government on a daily basis for household purposes (especially for drinking and cooking purposes). The depth of domestic shallow tube-wells (< 140 ft) is lesser compared to deep tube-wells (> 500 ft) (Goel et al. 2019, van Geen et al. 2003). The easy installation and use of STW naturally propagates consequent arsenic withdrawal leading to harmful human health risks, which includes cancer (skin, lung and bladder) (Argos et al. 2010, Mohana et al. 2020, Naujokas et al. 2013). A large population worldwide is facing carcinogenic health risk due to acute and chronic toxicity of arsenic through consumption of groundwater, which is documented as a severe environmental health concern (Celik et al. 2008, Chakraborti et al. 2013, Smith et al. 2009). Exposure to arsenic toxicity causes numerous health hazards in humans like pigmentation, cancer (skin, lung, and bladder), melanosis, keratosis, etc. (Abbas et al. 2018, Chakraborti et al. 2018, Roychowdhury 2010). Considering the toxic potentiality of arsenic, World Health Organization (WHO) has suggested the recommended value of arsenic as 0.01 mg/l in drinking water (Shakoor et al. 2016, WHO 2011).