The distribution of drinking-tea-borne fluorosis in the six ethnics in Qinghai Province / 中华地方病学杂志

ABSTRACT

Objective To find out the distribution of drinking-tea-borne fluorosis in the six ethnics in Qinghai Province, and to provide basic data for prevention and control of the disease. Methods In 2010, according to the requirement of “The National Surveillance Program of Drinking-Tea-borne Fluorosis”, six ethnics accounted for 99.59% of total population in Qinghai Province were investigated in 28 counties having brick-tea drinking habit. Three townships and a town in each county, two administrative villages(residents’ committee) in each township and town were chosen and 50 adults in each administrative village and residents ’ committee were selected to check skeletal fluorosis, dental fluorosis, urine fluoride and daily drinking amount of tea water. Five to six samples of drinking tea water were determined. Dental fluorosis was examined by Deans method; the fluoride content of brick-tea and urine were determined by fluoride ion selective electrode; the skeletal fluorosis was diagnosed based on “Endemic Osteofluorosis Clinical Indexing Diagnosis Standard”( WS 192-2008 ) . Results A total of 10 335 adults were surveyed, the number of Tibetan, Han, Hui, Mongolian, Tu and Salar ethnics were 4 972, 3 063, 1 196, 634, 235 and 235, respectively. The daily drinking amounts of tea water in Mongolian, Tibetan, Hui, Tu, Han and Salar ethnics were 2.53, 2.19, 1.74, 1.63, 1.22 and 1.07 L, respectively. Daily fluoride intakes in Tibetan, Mongolian, Tu, Hui, Han and Salar ethnics were 3.99, 2.78,2.27, 2.16, 1.78 and 1.28 mg, respectively. The medians of urinary fluoride concentration of the Tibetan, Tu, Hui, Han, Mongolian and Salar ethnics were 1.46, 1.19, 1.12, 0.98, 0.93 and 0.81 mg/L, respectively. The prevalence rates of dental fluorosis of the Hui, Han, Tibetan, Tu, Mongolian and Salar ethnics were 34.53%(413/1 196), 27.07%(829/3 063), 21.60%(1 074/4 972), 20.00%(47/235), 17.98%(114/634) and 6.38%(15/235), respectively. The incidence rates of clinical skeletal fluorosis of the Tibetan, Mongolian, Han, Hui, Tu and Salar ethnics were 13.42%(667/4 972), 11.04%(70/634), 9.31%(285/3 063), 7.61%(91/1 196), 5.53%(13/235) and 4.26%(10/235), respectively. Conclusions The distribution and prevalent status of drinking-tea-borne fluorosis in the six ethnics of Qinghai Province are different. Tibetan and Mongolian ethnics are the key population concerning the prevention and control of the disease.