Distribution of fluoride and fluorosis in Ethiopia and prospects for control

A review and mapping of fluoride rest data for 270 water sources in 126 com munities and examination of the literature of fluorosis distribution in Eth iopia show that this health problem extends beyond the Rift Valley into som e highland communities. Fluoride concentrations above 5.0 mg/l in the Rift Valley were found mostly in hot springs (100% of all sources), lakes (78%), shallow wells (54%) and boreholes (35%) and the lowest concentrations (bel ow 1.5 mg/l) in springs and rivers. Analysis of hydrochemical, economic and demographic factors in the spatial distribution of high-fluoride domestic water sources indicates that the fluorosis problem has become more serious in the Rift Valley in recent decades. Considerable spatial variation in the occurrence of fluoride, even within the same communities, and the presence of some low-fluoride water sources in the Rift Valley offer possibilities for geochemical exploration for acceptable domestic sources. The defluorida tion programme in the Wonji irrigation scheme illustrates the problems face d by a large rural community in a developing country. Possibilities for con trol are examined and recommendations made for the development of alternati ve water sources and promising defluoridation methods using locally availab le materials and technologies.