Prevalence of Brick Tea-Type Fluorosis in the Tibet Autonomous Region.
BACKGROUND
The prevalence of brick tea-type fluorosis is high in Tibet because of the habit of drinking brick tea in this region. Brick tea-type fluorosis has become an urgent public health problem in China.


METHODS
A cross-sectional survey was conducted to investigate prevalence of brick tea-type fluorosis in all districts of Tibet using a stratified cluster sampling method. Dental fluorosis in children aged 8-12 years and clinical skeletal fluorosis in adults were diagnosed according to the national criteria. A total of 423 children and 1320 adults participated in the study. Samples of drinking water, brick tea, brick tea infusion (or buttered tea), and urine were collected and measured for fluoride concentrations by the fluoride ion selective electrode method.


RESULTS
The fluoride level in all but one of the brick tea samples was above the national standard. The average daily fluoride intake from drinking brick tea in all seven districts in Tibet was much higher than the national standard. The prevalence of dental fluorosis was 33.57%, and the prevalence of clinical skeletal fluorosis was 46.06%. The average daily fluoride intake from drinking brick tea (r = 0.292, P < 0.05), urine fluoride concentrations in children (r = 0.134, P < 0.05), urine fluoride concentrations in adults (r = 0.162, P < 0.05), and altitude (r = 0.276, P < 0.05) were positively correlated with the prevalence of brick tea-type fluorosis. Herdsmen had the highest fluoride exposure and the most severe skeletal fluorosis.


CONCLUSIONS
Brick tea-type fluorosis in Tibet is more serious than in other parts of China. The altitude and occupational factors are important risk factors for brick tea-type fluorosis.
Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health.
Zhipeng
Z
Fan
Yanhui
Y
Gao
Wei
W
Wang
Hongqiang
H
Gong
Min
M
Guo
Shengcheng
S
Zhao
Xuehui
X
Liu
Bing
B
Yu
Dianjun
D
Sun
D000328:Adult; D000531:Altitude; D001847:Bone Diseases / Q000139:chemically induced / Q000453:epidemiology*; D002648:Child; D003430:Cross-Sectional Studies; D004781:Environmental Exposure / Q000009:adverse effects* / Q000706:statistics & numerical data; D005459:Fluorides / Q000008:administration & dosage / Q000009:adverse effects*; D009050:Fluorosis, Dental / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D009790:Occupations / Q000706:statistics & numerical data; D015995:Prevalence; D012307:Risk Factors; D012720:Severity of Illness Index; D013662:Tea / Q000009:adverse effects* / Q000737:chemistry; D018609:Tibet / Q000453:epidemiology
D013662:Tea; D005459:Fluorides