目的　了解宁乡县灰汤镇 4个温泉型氟病区改水降氟 13年的防治效果。方法　采用横断面调查法。结果　 8～ 12岁学生氟斑牙患病率降至 30 %以下 ,学生尿氟含量已下降到 1.0 4mg/ L,较改水前 1983年的调查结果有明显的下降 (χ2 =45 2 .1881,t=2 7.2 0 6 1,P <0 .0 1) ,氟斑牙指数由 3.2 4下降到 0 .5 2以下 ,其流行强度由较显著流行降为轻微流行或阴性流行。氟对牙齿损害程度减轻 ,可疑和极轻的患者占整个病例的 73.19%。居民饮用水氟含量为 0 .35 mg/ L ,低于国家饮水卫生标准 1.0 0 mg/ L ,直接饮用温泉水人群下降到 4.5 % ,明显低于改水前的 5 3.2 5 % (t=44 .0 6 ,P <0 .0 1)。结论　该地区经过 10多年的改饮低氟水后 ,地方性氟中毒的防治取得了较明显的效果。 Objective To understand the preventive and therapeutic effects of water-and fluoride-lowering fluoride on four hot-spring fluorosis areas in Huitang Town of Ningxiang County for 13 years. Methods using cross-sectional survey method. Results The prevalence of dental fluorosis in students aged 8 ~ 12 years dropped to below 30%. The urinary fluoride content of students dropped to 1.04mg / L, which was significantly lower than that of the 1983 survey (χ2 = 45 2 .1881 , t = 2 7.2 0 6 1, P <0.01). The dental fluorosis index decreased from 3.2 4 to 0.52 or less, and the prevalence of the dental fluorosis decreased from significant to mild or negative. Fluoride to reduce the extent of damage to the teeth, suspicious and very light patients accounted for 73.19% of the total cases. The fluoride content of drinking water was 0.35 mg / L, lower than 1.0 0 mg / L of national drinking water standard, and the direct drinking of hot spring water dropped to 4.5%, which was significantly lower than that of before drinking water (52.2%, t = 44 .0 6, P <0 .0 1). Conclusion After more than 10 years of drinking low fluoride water in the area, the prevention and cure of endemic fluorosis has achieved obvious effects.