Probabilistic human health risk assessment from groundwater fluoride contamination in Main Ethiopia Rift

Fluoride toxicity has become a significant global public health concern, with drinking water being a major source of exposure. This study aimed to determine groundwater fluoride concentration and assess its non-carcinogenic health effects on human health. A longitudinal study design was applied to select water samples in dry and wet seasons from Adama City and Wenji Gefersa town of Ethiopia. Groundwater fluoride concentration was measured using an ion-selective electrode. Total hazard analysis was assessed based on the chronic daily oral intake and dermal absorbed dose of fluoride. Analyses were conducted using ArcGIS, an Excel spreadsheet and Statistical Packages for the Social Sciences (SPSS). This study reported that groundwater fluoride concentration ranged from 0.3 mg/L to 38 mg/L, with the mean annual concentrations of Adama City and Wenji Gefersa Town being 1.9 mg/L and 23 mg/L, respectively. Fluoride concentrations reported at 70% and 45% of groundwater samples during the wet season and dry season were above World Health Organization (WHO) guidelines for drinking water. Total hazard index values among sampled locations varied from 0.17 to 30.43. Three-fourths of infants, 99% of children, 62% of adolescents, and 45% of adults had a risk of developing a non-carcinogenic health effect. This study demonstrated fluoride contamination of groundwater sources pose the residents for higher probability of developing non-carcinogenic health effects on their lifetimes. Application of locally available defluorination technology is paramount to safeguard the community.