Assessment of health hazard due to fluoride in groundwater from a rural area in east-coast of India and remedial measures

The present research deals with the quantification of health hazard in a fluorosis prone area from east-coast of India. The average health hazard quotients are 2.09, 2.42, 1.79, and 1.69 for infants, children, male, and female adults, respectively. These values are more than the tolerance limit (1) in 92% groundwater samples and 96% of the study area. The children are more vulnerable to fluorosis than infants and adults. Ca²⁺/ Na⁺ versus HCO₃⁻/Na⁺ and Ca²⁺/Na⁺ versus Mg²⁺/Na⁺ plots suggest silicate weathering as the prime factor while linear relationship of TDS versus NO₃⁻ + (Cl⁻/HCO₃⁻) supports the anthropogenic input of F⁻ to the aquifer system. The study suggests that the F⁻ ions are chiefly derived from fluorite, apatite, biotite, and hornblende present in the granitic basement under alkaline environment. The secondary sources are domestic and industrial sewage as well as return flow from irrigation with ingredients of phosphate fertilizers. The adverse effects of fluorosis can be minimized by mass awareness programmes, alternative source of potable drinking water, defluoridation techniques, dilution of high F⁻ concentration in groundwater, and minimizing the use of phosphate fertilizers.