A Pioneering Study on Spatial-Temporal Variability and Probabilistic Health Risk Assessment of Fluoride in Natural and Artificial Lakes from Turkey

Abstract

Spatial-temporal variability of fluoride in water has been a major global health concern. However, in Turkey, there has been very limited research quantifying the probabilistic health risks from fluoride accumulations in the water of natural-artificial lakes. Thus, we aim to determine the spatial-temporal variability and probabilistic health risk of fluoride exposure in the water of stagnant water bodies in the Thrace region (Turkey). A total of 33 stagnant water bodies were selected, and water samples were collected during the dry and wet seasons of 2021–2022. The fluoride levels were measured by using a spectrophotometric method, and the estimated daily intake (EDI) and hazard quotient (HQ) were calculated using the health risk model. The seasonality and spatial-temporal variability of the fluoride content in the water of natural and artificial lentic environments were examined. The fluoride accumulations varied from 0.16–0.64 mg/L for the natural lakes, 0.04–0.74 mg/L for the reservoirs, and 0.01–0.53 mg/L for the artificial ponds. The study area had a fluoride deficiency of less than 0.5 mg/L in natural water bodies during the wet season (87.87%) and the dry season (93.93%), which might be a potential health threat. All the calculated HQ values, both in the dry and wet seasons and in all age groups, were recorded as 1. Both teenagers and children living in the central part of the study area are at higher risk than infants and adults. To evaluate model uncertainty, Monte Carlo simulations were employed. The outcome of the sensitivity analysis revealed that the major risks to the health of inhabitants are the high content of fluoride and their daily intake of water. Overall, a case-sensitive study should be conducted to investigate further health impacts from drinking low fluoride-containing water in the study region.