Increasing fluoride in groundwater : A scenario

Abstract

Groundwater is the major source for various purposes in most parts of the world. In the present time because of the developmental activities, changing agricultural practices, life styles, food habits etc. ground water contamination is increasing. Presence of low or high concentration of certain ions is a major issue as they make the groundwater unsuitable for various purposes. Fluoride is one such ion. Fluoride concentration of at least 0.6 mg/L is required for human consumption as it will help to have stronger teeth and bones. Consumption of fluoride above 1.5 mg/L results in acute to various forms of fluorosis. Presence of low or high concentration of fluoride in groundwater is because of natural or anthropogenic causes or a combination of both. Natural sources are associated to the geological conditions of an area. Several rocks have fluoride. Anthropogenic sources of fluoride include agricultural fertilisers and combustion of coal. Since ingestion of high fluoride has a long term effect on human health it is essential to monitor its concentration in groundwater used for drinking periodically and take steps to bring them within the permissible range of 0.6 to 1.5 mg/L. Such conditions prove the importance of Water Resources Management. There are several methods available for the removal of fluoride from groundwater. To dilute the ground water contaminated with fluoride, building artificial recharging structures; which will decrease its concentration. Rainwater harvesting through existing wells also will prove effective to reduce the groundwater fluoride concentration. Methods like adsorption, ion exchange, reverse osmosis, electro-dialysis etc can be practiced at community level or at households to reduce fluoride concentration. But the choice of each method depends on the local conditions of the region and source of contamination. Fluoride contamination being a prominent and widespread problem in several parts of India educating the people and providing safe drinking potable water by adopting best water resource management practices is essential for a healthy nation.