Abstract

High concentration of fluoride in the groundwater is observed to be associated with granitic aquifers as well as near phosphate mines around the globe. The present work is a hydrogeological study of the ground water of Beldih phosphate mines in India. Being located in the Singhbhum shear zone the area has a complex tectonic history and is dominated by phosphate, alkali granites, amphibolites, and granitic gneiss with higer abundance of fluoride bearing minerals like apatite and biotite. Total of 12 water samples were collected for a preliminary study to assess the spatial variation of fluoride in ground water and surface water with an aim to understand the effect of phosphate mines in elevating fluorosis in adjoining areas. The groundwater chemistry shows a trend that the concentration of fluoride and nitrate gets elevated as we approach towards the open cast phosphate mines. From the spatial observation combined with the water chemistry and geology it is evident that the apatite dissolution is the prime cause of the elevation in fluoride concentration. However presence of iron in the lithology controls the fluoride level to some extent. Since the area is effected with high fluorosis its can be concluded that the groundwater geochemistry along with the air borne fluoride present in the phosphate dust are the major cause of the fluorosis. The exploration of phosphate must be carried out with out most environmental care and the mitigation of post mining effect should be planned before mining operation. Fluorosis is an irreparable health hazard and a major geohealth concern that has already affected a large amount of population.