
To prevent adverse health effect related to fluoride overdoses in drinking water, a comprehensive study is presented in this work for determining the optimal fluoride concentration range in drinking water. In fact, the optimal concentration range is bordered by two thresholds. For the hyper sensitive age groups (infant and children) the optimal concentration of 0.5mg.L-1 is required. This optimal concentration is known as the down threshold. However, for less sensitive age groups (adult), the optimal concentration of 1mg.L-1 is taken as the upper threshold. This study proposes also a numerical model to describe the daily fluoride exposure depending on the subject age via drinking tap water. In order to minimize the error between reference values (safety limit) and calculated values;the model is calibrated by means of an algebraic adjustment with introduce a correction factor.