a brief and critical review of endemic hydrofluorosis in rajasthan, india

Almost all the drinking water sources, in the rural areas of the 33 districts of rajasthan, the largest state in india, are contaminated with varying amounts of the fluoride ion (f). most of the sources, from groundwater, bore-wells, and hand-pumps, contain f beyond the country standard for india set by the bureau of indian standards, a requirement (acceptable limit) of 1.0 ppm (mg/l) or a permissible limit in the absence of an alternate source of 1.5 ppm, or the world health organization “desirable” upper limit of 1.5 ppm. no extensive epidemiological studies on water-borne hydrofluorosis (chronic fluorosis) have been conducted in many of these endemic high drinking water f level districts. however, many reports on endemic hydrofluorosis in villagers and their domesticated animals are available from southern rajasthan and in the present review these are critically reviewed and areas for possible future research are identified. the review considers the sources of f exposure, the distribution of f in potable water, f tolerance and the development of hydrofluorosis, the clinical features of chronic f toxicity, factors affecting the severity of f toxicity, biomarkers for chronic f poisoning, and the mitigation and prevention of hydrofluorosis. these factors may be useful in the framing and implementation of health policies at the state level for the mitigation and control of endemic hydrofluorosis.