Fluoride Problems in Sri Lanka

Argues that excessive fluorides in groundwater are a serious water quality problem in some parts of Sri Lanka. The incidence of dental fluorosis shows a high correlation with the presence of groundwater in certain areas. Tube wells constructed in various rock types have shown different fluoride concentrations, possibly due to the different mineral constituents in these rocks and their relative capability of releasing fluoride ions into groundwater. It has been observed that the tube wells located in the dry zone have higher fluoride concentrations than those in the wet zone. The fluoride contents of groundwater show an inverse relationship with average yields of the tube wells, indicating the inverse relationship of aquifer permeability to the fluoride content in groundwater.