A five-year study of the occurrence of fluoride in groundwater from Brčko District

Fluoride is a natural component of groundwater resources and has considerable impact on human health. Epidemiological studies showed that low concentration of fluoride (below 0.5 mg/L) in drinking water leads to dental caries while fluoride content of between 0.5 and 1.5 mg/L promotes dental health. It was also reported that the assimilation of fluoride from drinking water with concentrations above 1.5 mg/L might result in dental, skeletal and crippling fluorosis. Dental fluorosis is the most common manifestation of chronic use of high fluoride water and it has the greatest impact on the growing teeth, particularly on children under seven years of age. On the other hand, the fluoride content in the groundwater is a function of many factors such as pH, temperature, dissolution of natural minerals in the rocks and soils with which water interacts. For all reasons mentioned, the aim of this study is to present a systematic approach to evaluate the distribution of fluoride in the groundwater of Brcko Distrikt. The samples were collected from 61 groundwater sources (1580 samples) during 2004 – 2008. The fluoride concentration was determined by ion chromatography with chemical suppression of eluent conductivity using the ISO 10304-1 method. The obtained results showed that the concentrations of fluoride found in the studied groundwater ranged between 0.024 to 1.085 mg/L, and the average value is 0.428 mg/L. The minimum fluoride content in all samples of this region was measured in June 2007, while the maximum fluoride value was in February 2004. Furthermore, the mean fluoride value of year did not change significantly within the five years (0.402 – 0.456 mg/L), and only all measured concentrations in 2005 were below 1 mg/L. It is also observed that about 75% of the investigated groundwaters contain less than 0.5 mg/L fluoride. The obtained results demonstrate that the concentrations of fluoride in all samples were below the maximum permissible limit (1.5 mg/L) established by WHO for this essential component. Our study suggests in general that the fluoride concentration in groundwater of Brcko is low. Furthermore, the results indicated that total daily fluoride intake by people living in this region needs to be determined, and a research program in this regard has been initiated.