Effects of Fluoride Contents in Ground Water: a Review

Ground water is the major source of freshwater on the earth. Groundwater containing dissolved ions beyond the permissible limit is harmful and not suitable for domestic use. Fluoride beyond desirable amounts (0.6 to 1.5mg/l) in groundwater is a major problem in many parts of the world. The fluorides belong to the halogen group of minerals and are natural constituents of the environment. Fluoride is the most electronegative of all chemical elements and is never encountered in nature in the element form. Though fluoride enters the body through water, food, industrial exposure, drugs, cosmetics, etc., drinking water is the major source (75%) of daily intake. World Health Organization (WHO) and IS: 10500 recommend that the fluoride content in drinking water should be in the range of 1.0 to1.5 ppm. Intake of more fluoride, results in multidimensional health manifestations, the most common being dental and skeletal fluorosis. This problem is severe in India and need immediate attention of government, donors and philanthropists to save our people. Suitable measures such as defluorinating the groundwater before use and recharging the groundwater by rainwater harvesting need to be practiced to improve the groundwater quality in this area. Many Defluoridation devices and techniques, which includes Actinated Alumina, Red mud, Nalgonda technique, Magnesia & Montmorillonite have been referred with various limitations. Comparing all defluoridation devices, the most feasible option for fluoride removal for rural regions seems to be magnesia. It is selective for fluoride removal as it binds well with fluoride ions.