Fluoride concentration in potable groundwater in rural areas of Khaf city, Razavi Khorasan Province, northeastern Iran.

Long-term exposure to high concentrations of fluoride is associated with several adverse effects on human including dental and skeletal fluorosis. We studied all the groundwater wells located in rural areas of Khaf city, Razavi Province, northeastern Iran between 2009 and 2010. Fluoride concentration of water samples was measured by SPADNS method. We found that in rural areas the fluoride concentration ranged from 0.11 to 3.59 ppm-the level was less than the permissible limit in 31% of studied samples, higher than the permissible limit in 4% of the samples, and within the optimum limit of 1 to 1.5 ppm in 65% of water samples.