汕头市地方性氟中毒病区改水后小学生尿氟及氟斑牙患病调查

Epidemiological Analysis of Urine Fluoride Contents and Dental Fluorosis in Pupils in Endemic Fluorosis Areas in Shantou,Guangdong after Water Improvement

目的调查汕头市地氟病区改水后水氟浓度与小学生尿氟及氟斑牙患病情况,以评价改水降氟的效果。方法于2009年选择汕头市潮南区改水后4个氟病区村作为调查点,以1个非氟病区村作为对照,测定水氟浓度。对8～12岁当地出生的4580名小学生进行氟斑牙患病情况调查,随机抽取550名学生测定尿氟浓度。结果水氟浓度均低于1mg/L。改水年限9年以上的氟病区村氟斑牙患病率基本达到非氟病区的标准。小学生尿氟浓度与氟斑牙分度和患病率均呈正相关(氟斑牙分度:r=0.997,P<0.01;氟斑牙患病率:r=0.994,P<0.01)。当尿氟浓度高于1.2 mg/L时,小学生氟斑牙患病率高于30%。结论汕头市地氟病区经改水降氟后,饮用水符合卫生要求,大部分氟病区村小学生氟斑牙患病率已达非氟病区村的水平。

Objective Through the investigation of fluoride contents in drinking water and urine and dental fluorosis in pupils in the endemic fluorosis areas in Shantou, Guangdong to evaluate the effects of water improvement. Methods Four villages were chosen as the investigation subjects in the endemic fluorosis area in Shantou where water improvement was finished and one village in non-fluorosis area as the control. The contents of fluoride in drinking water of the 5 villages were determined. Four thousand and five hundred and eighty pupils aged 8 to 12 years in the 5 villages were investigated for the dental fluorosis and 550 pupils were randomly chosen for the determination of the urine fluoride. Results The fluoride contents in drinking water of all samples from the 5 villages were not more than 1 mg/L. More than 9 years after water improvement, most of the prevalence rates of dental fluorosis in pupils in endemic fluorosis area were below 30%, dose-dependent manner was observed between urine fluoride and prevalence rate of dental fluorosis （r=0.994, P〈0.01）, and between urine fluoride and classification of dental fluorosis （r=0.997 ,P〈0.01）. The prevalence rate of dental fluorosis will be below 30% when the urine fluoride was not more than 1.2 mg/L. Conclusion After water improvement in endemic fluorosis areas in Shantou, Guangdong, the content of fluoride in drinking water conformed with the national standard, and the prevalence rate of dental fluorosis has decreased almost to the same in the non-fluorosis area.