An investigation on drinking brick-tea type fluorosis of children in Guoluo Prefecture of Qinghai Province in 2017

Objective To explore the prevalence state of drinking brick-tea type fluorosis in children in Guoluo Prefecture, Qinghai Province. Methods According to the historical prevalence of drinking tea-type fluorosis in Guoluo Prefecture, in 2017, in 5 counties of Guoluo Prefecture, according to the pastoral area, agricultural area, semi-agricultural and semi-pastoral areas, each township(town) was selected, in each township (town) drawed a natural village in a ward as a survey point. At each survey site, drinking water samples of local residents were collected, and 10 households were selected, tea samples were collected, and dental fluorosis was investigated for children aged 8-12 years old. The mean of fluoride was determined by fluoride ion selective electrode method (GB/T 5750.5-2006, GB 19965-2005), and the dental fluorosis was diagnosed based on "Diagnosis of Dental Fluorosis" (WS/T 208-2011). Results The mean of fluoride in 85 water samples was 0.34 mg/L (0.20-0.77 mg/L), the mean of fluoride in 161 brick-tea samples was 579 mg/kg (110-1 278 mg/kg). The mean of daily fluoride intake of each person was 6.78 mg, among them, 73.29% (118/161) drank brick-tea, the detection rate of dental fluorosis of 2 083 children was 22.85% (476/2 083), and the index of dental fluorosis was 0.42, the prevalence was weak. Conclusion The prevalence of drinking brick-tea type fluorosis of children in Guoluo Prefecture is less serious. Key words: Child; Fluorosis, dental; Brick-tea; Investigation