西藏的环境氟水平与砖茶型氟中毒

为探讨西藏儿童与砖茶型氟中毒的关系,以拉萨为中点,藏北那曲为北部点,定日县为南部点,对这3个地区的土壤、燃料、水源和主要食物进行了氟含量测定.采用世界卫生组织(WHO)和世界粮农组织(FAO)提出的<化学污染物的膳食摄入量研究指南>,进行了食物结构、饮茶习惯、儿童食物摄入量以及儿童每日总摄氟量的调查按美国国家牙科研究所Horowitz提出的标准进行了儿童氟斑牙检查.结果表明,3个调查点均属传统的低氟区,而儿童每日摄氟量高,那曲8.03mg,拉萨6.93mg,定日7.68mg.其原因来自含砖茶的食品酥油茶和糌粑(青稞粉拌砖茶水的食物).这2种食物占日总摄氟量的99.74%(那曲),98.70%(拉萨),99.60%(定日),砖茶氟摄入导致西藏儿童砖茶型氟中毒的流行.氟斑牙患病率分别达到82.66%(那曲),52.89%(拉萨),75.93%(定日),氟斑牙指数表明,那曲、定日属氟中毒重度流行区,拉萨属中度流行区.砖茶型氟中毒是我国近年来发现的氟病新类型,与饮水型、燃煤污染型比较,它具有覆盖面大、隐蔽性强、难以防治的特点,降低砖茶氟含量可能是防治砖茶型氟中毒的最好方式.

Fluoride in The Environment and Brick-Tea-Type Fluorosis in Tibet

To explore whether endemic fluorosis in Tibet is related to local factors, an epidemiological survey of fluorosis was conducted in 3 districts in Tibet. The survey used the WHO and FAO established "Guideline for the study of dietary intake of chemical contaminants" and the Horowitz suggested criteria for children dental fluorosis examination. The fluorine in the local environment of the 3 selected districts was studied in detail. The possible fluorine sources examined indicated that only the brick-tea carried a high content of fluoride; water, other food materials, and fuel contents were insignificant. The children daily fluorine intake was high, where Naqu was 8.03 mg, Lahsa was 6.93 mg, Dingri was 7.68 mg. All the dietary fluoride was come from the brick-tea processed foods: the buttered-tea and zamba, these two contributed 99.74%, 98.70% and 99.60% of their daily fluorine intake respectively. The dental fluorisis index indicated that Naqu and Dingri were severe epidemic and Lahsa was moderate epidemic. The endemic fluorosis that occurs in Tibet was essentially due to heavy consumption of foodstuffs prepared with brick-tea, however, the high altitude, harsh living conditions, and poor nutritional status aggravated the fluorosis. Brick-tea type fluorosis is a new type of fluorosis recently discovered in China. Compared with the drinking water type and coal combustion type of fluorosis, it covered extensive area, more covert, and difficult to control. Decrease the fluorine content of brick-tea might be the most promising measure.