According to WHO guidelines, the concentration of fluoride in the drinking water should be about 0.8 mg/L and 1.5 mg/L is given as maximum allowable concentration. It is however the opinion of the Author of this paper that these values are estimated from old literature, before introduction of systematic fluoridation of tooth pastes. They are also estimated, having as a background, non-fluorotic (European) areas. WHO wisely leaves the selection of Water Standards to national authorities. Unfortunately many developing countries are left behind with respect to capacities of erecting qualified bodies for selection of appropriate health based Standards.
In a fluorotic area like the Arusha region, which is a part of the Rift Valley, the WHO guidelines are of very little value, as the uncontrollable ingestion of fluoride through food and soft drinks is already higher than normal and out of control. In such areas special standards are recommended:
In such areas, whenever defluoridation is practiced, one could aim at a concentration in the drinking and cooking water of about 0.5 mg/L on daily operation and then 0.8 mg/L at maximum.
Written by Eli Dahi March 2009