Assessment of Groundwater Quality and Associated Human Health Risk of Central Gujarat, India

The groundwater quality of Vishwamitri River Basin (VRB), Central Gujarat, is assessed to evaluate its competency to meet the agricultural and drinking standards, and to determine associated human-health risk by consumption of this groundwater, if any. The overall groundwater quality for drinking is expressed by water quality index. Various indices like sodium adsorption ratio, salinity hazard, soluble sodium percentage, magnesium adsorption ratio, and Kelly's ratio represent groundwater's agricultural suitability. A health risk assessment model is used to measure non-carcinogenic human health hazard. Results reveal that i) trace metals like lithium, manganese, molybdenum, strontium, thallium, vanadium and zinc are present in groundwater indicating contamination of groundwater by hazardous industrial and agricultural wastes; ii) groundwater of about 78% of VRB area is unsuitable for drinking; iii) positive values of Schoeller index of maximum groundwater samples indicate that ion exchange of Na+ and K+ with Ca(2+)and Mg2+ is the dominant mechanism to control the quality of groundwater; iv) SAR values indicate high to very high salinity of groundwater and therefore, it is unsuitable for irrigation; and v) the health risk assessment model discloses that the risk of gastrointestinal disorder is higher in children than adults; and oral ingestion is more dangerous than dermal exposure.