Drinking tea type of endemic fluorosis in Xinjiang in 2014-2016

Objective To understand the levels of water fluoride, tea fluorosis and the severity of drinking tea type of endemic fluorosis in Xinjiang from 2014 to 2016, and to provide a basis for making prevention and control measures. Methods In 2014-2016, a cross-sectional study was conducted to select six counties with serious fluorosis in Xinjiang as monitor counties, one diseased township was selected from five directions including east, south, west, north and center in each county, one village was selected in each township, and 10 families were selected to investigate the situation of brick tea drinking. Drinking water and brick tea samples were collected for detection of fluorine content, and epidemiological methods were used to analyze the prevalence of dental fluorosis and skeletal fluorosis. Results In 2014-2016, resident population per capita brick tea consumptions were 3.9-4.4 kg, per capita brick tea fluorine intakes were 4.6-6.1 mg, and the mean of tea fluorine was 433.1, 385.2, 432.7 mg/kg, respectively, the differences were not statistically significant (F= 0.33, P > 0.05); the means of water fluorine were 0.06-1.26 mg/L, and they were 0.38, 0.37, 0.33 mg/L, respectively, the differences were not statistically significant (F= 2.64, P > 0.05). The survey results showed that dental fluorosis of children aged 8-12 was 243 in three years, with a detection rate of 4.47% (243/5 442) and the range of 0.08-0.14, which was negative. The skeletal fluorosis of adults aged 36-45 was 25 in 2015, with a detection rate of 2.75% (25/910). Conclusions The fluorine content of some tea in drinking tea type of endemic fluorosis areas in Xinjiang is high, and the fluorine content of some water samples has exceed the standard of drinking water type disease area (1.2 mg/L). The prevalences of dental fluorosis and skeletal fluorosis are acceptable; it is recommended to maintain the previous prevention and control policies and to further monitor the tea market. Key words: Fluorine; Fluorosis, dental; Water; Tea