Brick-tea type fluorosis in monks in Qinghai Province

Abstract

Objective To know the distribution and harm of brick-tea type fluorosis in monks in Qinghai Province. Methods Twenty-eight temples were selected as survey sites from 28 counties of Qinghai Province. The amounts of drinking tea-water of each monk and the brick tea capita consumption per temple each year were recorded. Drinking water, tea water and urine samples of monks were collected and fluorine content was tested; dental fluorosis of children aged 8 - 12 years and of adult monks over the age of 16 were examined; clinical skeletal fluorosis of monks 16 years of age and older and X-ray skeletal fluorosis of all adult monks in the temple were examined. Fluorine content in drinking water, brick tea and urine was tested using F-ion selective electrode. Dental fluorosis was checked using the dental fluorine diagnostic criteria （WS/T 208-2001 ）, and skeletal fluorosis was diagnosed based on the endemic skeletal fluorosis diagnosis standard （WS 192-1999）. Results A total of 28 copies of drinking water samples were tested, and mean water fluoride was （0.26± 0.13） mg/L; in the 69 copies of brick tea, the mean fluoride value was 667.12 mg/kg; a total of 777 adult monks, the average daily drinking water of brick tea was （1 943.93 ±1 078.93）ml; a total of 224 children monks, the average daily drinking water of brick tea was （795.09± 389.81）ml; annum per capita consumption of brick was 5.30 kg; adult daily fluoride intake was 4.47 mg, child was 1.83 mg; the prevalence rate of dental fluorosis was 29.07% （291/1 001）,the prevalence rate of dental fluorosis of 8 - 12 years old children was 39.74% （93/234）, the adult was 26.00% （202/777）; the prevalence rate of clinical skeletal fluorosis was 4.76% （37/775）; and the prevalence rate of X-ray skeletal fluorosis was 4.88%（2/41）. The geometric mean of adult urinary fluoride was 1.11 mg/L（0.15 - 10.00 mg/L） of the 777 copies of urine samples tested, and that value of children was 1.23 rag/L（0.08 - 6.62 mg/L） of the 224 copies of samples. Conclusions The amount of annual brick tea consumption and daily intake of fluoride are big; brick-tea type fluorosis is serious and widely distributed in monks, so effective measures to control the epidemic are in urgentneed. Key words: Monks ; Tea; Fluoride ; Poisoning