Spatiotemporal distribution of fluoride in drinking water and associated probabilistic human health risk appraisal in the coastal region, Bangladesh

Abstract Spatiotemporal distribution of fluoride in drinking water has been posing serious health concerns worldwide. However, in Bangladesh, to date, there is a very limited study reported the probabilistic health risks from fluoride content in drinking water. Therefore, we investigate the spatiotemporal distribution of fluoride concentration in drinking water and associated health risks in the coastal districts of Bangladesh based on randomly collected 840 groundwater samples (Dry-season = 302 and Wet-season = 538). Probabilistic health risk appraisal from fluoride was performed using the Monte-Carlo simulation and sensitivity analysis. Fluoride concentration in 11.89% (Wet-season) and 24.50% (Dry-season) of the samples exceeded the acceptable level of 1.0 mg/L, while 3.90% (Wet-season) and 7.28% (Dry-season) samples surpassed the maximum permissible limit (fluoride: 1.5 mg/L. The deficiency of fluoride content in groundwater (  1) in both seasons. However, the risk of children and infants at the 95th percentile crossed the safe level (SL: 1) in the wet season and the risk of infants, children, teens and adults at the 95th percentile surpassed 1 in the dry season, indicating the potential adverse health effects. Apart from the high exposure, fluoride deficiency might be a severe problem in this region due to the very low concentration of fluoride (