Benchmark dose of the children's total fluoride intake / 中华地方病学杂志

ABSTRACT

Objective:By exploring the source of children's total fluoride intake and the relationship between children's total fluoride intake and dental fluorosis prevalence, to calculate the benchmark dose (BMD) of children's total fluoride intake and its 95% confidence lower limit (BMDL), and to provide the basis for revision of "Total Fluoride Intake for Inhabitants" (WS/T 87-2016).Methods:The villages that had water improvement for 5 years and more in 6 provinces of Jiangsu, Shandong, Hebei, Anhui, Henan and Shaanxi were selected as survey sites in April 2014. The water fluoride content of these villages was 0.3 - 3.0 mg/L, tap water samples from the centralized water supply were collected, and fluoride content was detected by ion selective electrode method. Children aged 8 to 12 years were selected, children's dental fluorosis was checked by Dean's method. Children's dietary and drinking water volume were surveyed by duplicate portion study (measurement for 3 d), and dietary fluoride content was detected according to the "Method for Determination of Fluorine in Foods". The mean and standard deviation of drinking water fluoride intake, dietary fluoride intake, and total fluoride intake were measured. According to the dose-response relationship between children's total fluoride intake and the detection rate of dental fluorosis, BMD and BMDL were calculated, and the reference dose (RfD) was calculated based on BMDL.Results:The mean of water fluoride of all 29 villages was 1.26 mg/L (from 0.41 to 2.85 mg/L). Totally 3 043 children aged 8 to 12 years were checked, and the detection rate of dental fluorosis was 30.2% (919/3 034). The lowest detection rate of dental fluorosis was 2.0% (2/100) and the highest was 71.4% (30/42) in the 29 villages. The children's dietary and drinking water volume of 769 person-time aged 8 to 12 years were surveyed, the children's daily drinking water fluoride intake, dietary fluoride intake, and total fluoride intake were (0.83 ± 0.66), (1.13 ± 0.61) and (1.96 ± 0.89) mg/d, respectively. The BMD of children's daily total fluoride intake was 2.43 mg, the BMDL was 2.21 mg, and the RfD was 2.21 mg.Conclusion:The BMD of 8 to 12 years old children's daily total fluoride intake is the same as the allowable limit (2.4 mg) of the national standard "Total Fluoride Intake for Inhabitants" (WS/T 87-2016).