Characterization of arsenic contaminated groundwater from central Bangladesh: Irrigation feasibility and preliminary health risks assessment

Abstract

Abstract To observe the current hydro-geo-chemical condition of shallow aquifers and the response from anthropogenic activities as well as to study the arsenic contents and affiliated health risks, groundwater samples from different parts of north-central Bangladesh (Tangail) were studied. In doing so, analytical parameters, including pH, total dissolved solids, electrical conductivity, dissolved oxygen, NO3-, HCO3-, Cl-, SO42-, Na, K, Ca, Mg, Fe, Cr, Mn, Ni, As, Cu, Cd, Zn, and Pb abundances were utilized. Aquifer hydrochemistry presents mainly Ca-Mg-HCO3 type water, while in some cases appreciable amount of Na+ and Cl- proclaim their presences in the formation of groundwater mineralogy. Therefore, there was significant impact from irrigation return flow to affect the groundwater hydrochemistry of this region. Source rock-water interactions in the form of dolomite and calcite weathering is the chief natural agent to provide minerals in the groundwater. The waters in the aquifer seem to be comparatively young with mostly being unsaturated in terms of carbonate minerals and having the scope of reverse ion exchange. Among the trace elements of this study average values of As, Mn, Fe, and Cd were above the guideline values, where As is the dominant contaminant in deteriorating the water quality. In terms of irrigation water indices, groundwater of the studied site is mostly suitable for agricultural usages. Although, magnesium hazard ratio and total hardness values can exert potential threats. However, As level in the studied groundwater possesses potential health hazardous for both non-carcinogenic and carcinogenic risks where children are more vulnerable than adults. The outcome this study invokes regular monitoring of groundwater quality, especially for As contamination to save the public-health.