The situation of brick tea type fluorosis in Inner Mongolia in 2009 and 2012

Objective To understand the trend of drinking-tea type fluorosis in the diseased areas in Inner Mongolia Autonomous Region,and to evaluate the effect of prevention and control measures.Methods In 2009 and 2012,6 monitored counties were selected in Inner Mongolia Autonomous Region; 5 diseased villages were selected in each monitored county,and 10 families were selected in each monitored village; fluorine content of brick tea was tested,and dental fluorosis conditions of all 8 to 12-year-old students and skeletal fluorosis conditions of all 36 to 45-year-old adults were examined.In 2012,in each monitored village,1 water sample of the drinking water source was collected respectively from five positions(east,south,west,north and the central of the village),and fluoride content of drinking water wastested.Results In 2009,the mean of brick tea fluorine content was 541.48 mg/kg in the monitored villages,and the fluoride content ≤ 300 mg/kg accounted for 17.62％.(49/278).In 2012,the mean of brick tea fluorine content was 536.06 mg/kg,and the fluoride content ≤300 mg/kg accounted for 11.00％(33/300).Total exceeding standard rate of the water fluoride content was 40.00％(12/30).In 2009,the detection rate of the children's dental fluorosis was 52.39％ (274/523),very mild,mild,moderate and severe cases accounted for 9.56％(50/523),19.86％(104/523),21.03％(110/523) and 1.91％(10/523),respectively.In 2012,the detection rate of the children's dental fluorosis was 35.71％(200/560),very mild,mild,moderate and severe cases accounted for 14.11％ (79/560),11.43％ (64/560),9.64％ (54/560),and 0.54％ (3/560),respectively.Compared with 2009,the proportion of moderate and severe cases reduced in 2012(W =40 696.0,P ＜ 0.01).In 2009,the detection rate of adult skeletal fluorosis was 23.52％ (167/710),mild,moderate and severe cases accounted for 17.32％(123/710),4.51％(32/710) and 1.69％(12/710),respectively.In 2012,the detection rate of adult skeletal fluorosis was 20.12％ (103/512),mild,moderate and severe cases accounted for 17.38％ (89/512),2.54％ (13/512) and 0.20％ (1/512),respectively.Compared with 2009,the proportion of moderate and severe cases reduced in 2012(W =12 797.5,P ＜ 0.01).Conclusion The drinking-tea type fluorosis in Inner Mongolia Autonomous Region has been controlled to some degree,but still serious in some areas;prevention and control measures need to be further strengthened. Key words: Fluorosis, dental;  Osteofluorosis;  Tea;  Urine