FLUORIDE CONTAMINATION IN GROUNDWATER OF HIREBUDURU AND GUNTRAL VILLAGES, DEVADURGA TALUK, KARNATAKA: SEASONAL AND SPATIAL VARIATIONS

Groundwater is the primary source of drinking water in many semi-arid regions of India, making its quality assessment crucial for public health. This study evaluates seasonal and spatial variations in fluoride contamination in groundwater of Guntral and Hirebudur villages, Devadurga Taluk, Karnataka, during 2020–21 and 2021–22. Physico-chemical parameters such as pH, electrical conductivity (EC), total dissolved solids (TDS), hardness, total alkalinity (TA), chloride, sulphate, and iron were analyzed along with fluoride levels across winter, summer, and rainy seasons. Fluoride concentrations in Guntral were consistently higher (8.9–9.5 mg/L) compared with Hirebudur (3.3–3.9 mg/L), exceeding permissible limits set by the Bureau of Indian Standards (IS 10500:2012) and the World Health Organization (WHO, 2017). Seasonal variation indicated maximum fluoride concentrations during the summer season, while spatial distribution identified Guntral as a hotspot of severe contamination. Elevated EC, TDS, and sulphates further highlighted deterioration of groundwater quality. The findings confirm that residents of these villages are at high risk of dental and skeletal fluorosis and call for urgent intervention. Mitigation strategies such as defluoridation techniques, awareness programs, and sustainable groundwater management are essential to reduce exposure and safeguard community health. Keywords: Groundwater quality; Fluoride contamination; Seasonal variation; Guntral; Hirebudur; Devadurga Taluk; Karnataka; Fluorosis; Public health