Assessment of groundwater quality of CKDu affected uddanam region in Srikakulam district and across Andhra Pradesh, India

Uddanam region in Srikakulam district of Andhra Pradesh, India, is a CKD hotspot with high prevalence of CKD of unknown etiology (CKDu). A number of investigators have suggested that groundwater contamination could be one of the factors contributing to the high prevalence of CKDu in this region. This study was focused on the monitoring and assessment of groundwater quality of Uddanam region and also in identifying potential etiological factors of CKDu from drinking water. Composite groundwater sampling was carried out in 40 selected villages in Uddanam region and 100 villages of other nine districts in Andhra Pradesh including Chimakurthy mandal (another CKD hotspot in this state) of Prakasam district during August 2018–May 2019. About 35% of villages in the study area had acidic groundwater (pH < 6.5) while only 3% villages had acidic groundwater in other districts. Moreover, groundwater had higher silica (SiO2) and lead (Pb) concentration in the groundwater samples were found to be above the BIS permissible limit (0.01 mg/l) in 55% of villages during pre-monsoon season. Fluoride (F−) concentration in groundwater was found well below the BIS permissible limit (1.5 mg/l) in 95% of villages of study area with mean concentration (0.54 mg/l, SD = 0.40). Synergic effects of lead, fluoride, silica and water hardness under acidic water can be potential causative agents for CKDu in the Uddanam region, hence need further investigation. In this study, analysis of organic contaminants such as pesticides and phthalates in groundwater samples of the study area were also carried out. Pesticides were not found in any groundwater samples, however, phthalates were detected in all water samples. Groundwater treated with RO process (from NTR Sujala RO plants) is recommended for drinking and cooking as a preventive measure for CKDu in Uddanam region.