Fluoride in groundwater, dates and wheat: Estimated exposure dose in the population of Bushehr, Iran

The goal of this study was to estimate the daily fluoride intake for residents of Bushehr province in southern Iran by determining their exposure to fluoride through consumption of drinking water, dates and wheat. The fluoride concentration of drinking water in this region varies between 0.5 and 3.0 mg/L, with an average of 1.6 mg/L; and 44.4% of the drinking water exceed the guideline value of 1.5 mg/L recommended by WHO. The average fluoride content of dates is 10.0 mg/kg; whereas wheat roots and shoots contain an average of 30.0 and 19.0 mg F−/kg, respectively. The estimated intake from drinking water is 0.12 mg/kg/d for children (20 kg body weight) and 0.05 mg/kg/d for adults (70 kg body weight). The total estimated fluoride intake (from drinking water and dates) for children is 0.17 mg/kg/d. Thus, dates contribute an average 30% to the daily fluoride intake in the population. The maximum estimated fluoride intake (from dates and drinking water) for children and adults are 3.4 and 1.6 times higher, respectively, than the minimum risk level of 0.05 mg/kg/d calculated by Agency for Toxic Substances and Disease Registry.

► The average fluoride content of the drinking water in Iran is high.
► Dates and wheat are potentially rich sources of fluoride.
► Staple foods must be considered for estimation of total dietary intake of fluoride.
► Both children and adults exceed the guideline values of fluoride exposure in Iran.