Fluoride occurrence and human health risk from groundwater use at the west coast of Urmia Lake, Iran

We investigated fluoride (F−) concentration and physicochemical features of groundwater in the Urmia coastal aquifer (northwest, Iran). Groundwater samples were collected during both dry (58 wells) and wet seasons (84 wells). Approximately 15 and 23% of the groundwater samples in the dry and wet seasons, respectively, exceeded the recommended F− value by WHO for drinking water (1.5 mg/L). High F− concentration in groundwater is mainly found in shallow wells. The cause of high F− concentration appears to be mainly caused by human activities. Agricultural fertilizers and industrial waste can result in rapid release of F− into the groundwater. Release of F− into the groundwater can, however, also be triggered by the interaction between rock and water. In the experimental area, high F− concentrations were found close to volcanic rocks. Health risks from exposure to F− in groundwater were analyzed for adults and children. Utilizing sensitivity analysis and Monte Carlo simulation, the uncertainties in the risk estimates were calculated. Sensitivity analyses showed that the most pertinent variables are F− concentration in drinking water, averaging time, exposure time, and ingestion rate of water. Children are more susceptible to the noncarcinogenic risk of F− in groundwater