An Investigation of Fluoride Contamination in Groundwater of Yadgir District, Karnataka

The study was taken up to investigate the fluoride concentration in the groundwater of Yadgir district. A total of ninety groundwater samples were collected from different locations of Yadgir, Shorapur, Shahpur taluks of Yadgir district during post monsoon season. The samples were collected and analysed for major cations and anions along with fluoride as per standard methods. The chronic exposure to higher level of fluoride of drinking water led to dental or skeletal fluorosis, the severity of the problem is directly related to its dose. The fluoride value of groundwater samples was found to range from 0.21 mg/L in Naganur village to maximum of 4.8 mg/L in Hurasgundagi village. The results of fluoride value indicated that 31.18 % of the groundwater samples had fluoride concentration exceeding the BIS permissible limit of 1.5 mg/L. An increasing trend in fluoride concentration was observed with respect to sodium (r = 0.72) and calcium (r=0.44), illustrating a positive and strong correlation between them in the study area. It was concluded that the fluoride-rich groundwater in the Peninsular Gneisses and granitic area of the study area, could be attributed to longer residence time and interaction with fluoride-bearing minerals in the bedrock in the study area. It was suggested to adopt Nalgonda de-fluoridation technique and better management practices of harvesting and conservation of rainwater to overcome the fluoride problem.