娄底市地方性氟中毒流行因素调查

Investigation on Epidemic Factors of Endemic Fluorosis in Loudi City

目的调查地方性氟中毒的病区变迁、目标人群氟斑牙患病率的变化、分析致病因素,为开展改灶降氟和长期的综合防治提供科学依据。方法检查学生氟斑牙、尿氟,比较不同年代不同病区学生患病率和尿氟水平;测定煤、制作藕煤的壤土、饮用水、大米、茶叶、改灶前后室内空气氟含量;测定人群防治知识知晓率。结果病区村从349个增加到1192个;学生氟斑牙患病率从47.64%下降至40.42%;重病区只限于海拔800m以上山区。检测煤氟含量为32.4～513.6mg/kg;壤土氟为139.0～1312.0mg/kg;干蔬菜、茶叶、大米含氟量均超过卫生标准。实施健康教育后居民和学生的地氟病防治知识知晓率从49.6%、44.8%提高到88.6%、92.4%。改灶后室内空气氟含量下降到0.019mg/m3以内。结论烧煤是导致地方性氟中毒病区扩大和患病人数不断增多的根本原因。制作藕煤的壤土氟含量高,是致氟中毒的重要氟源;村民冬春季节燃煤取暖,房屋无向外排气装置致室内空气氟含量高;主食大米、干菜、饮用水均含氟导致人体摄入过量而中毒。实施健康教育可显著提高居民和学生的地氟病防治知识。使用降氟炉灶可以有效降低室内空气氟浓度。

Objective To survey the area changes of endemic fluorosis and the changes of prevalence rate of dental fluorosis of target population,to analyze the pathogenic factors,and to provide the scientific evidence for making alteration and reducing fluoride in cooking stoves and carrying out long-term integrated control measures.Methods The students’ dental fluorosis and urinary fluoride were checked,and then the incidence rates of dental fluorosis and the levels of urinary fluoride of the students from different times and different areas were compared.The content of fluoride in coal,loam for producing briquet,drinking water,rice,tea,indoor air before and after improving cooking stoves was determined.And the awareness rate of prevention and treatment knowledge of the population was checked.Results Fluorosis villages increased from 349 to 1,192,while the prevalence rate of dental fluorosis of the students dropped from 47.64% to 40.42%.Severe fluorosis areas distributed in mountainous areas above 800 m.The content of fluorine in coal was 32.4～513.6 mg/kg.Fluoride in loam was 139.0～1,312.0 mg/kg.The content of fluoride in dried vegetables,tea,and rice exceeded the sanitation standard of safety.After the implementation of health education,the awareness rates of prevention and treatment knowledge of the residents and the students were both increased from 49.6% and 44.8% to 88.6% and 92.4%.After rebuilding cooking stoves,the content of fluoride in indoor air dropped to less than 0.019 mg/m3.Conclusions Coal burning is the basic reason for the enlargement of endemic fluorosis areas and the increasing number of the patients.High fluorine content in loam for producing briquette is the important source of fluorosis.High content of fluoride in indoor air results from villagers’ coal burning for warming houses in winter and spring but without an opening for outward discharge.Rice,dried vegetables,and drinking water which contain fluoride result in excessive intake of fluoride and fluorosis.Implementation of health education can significantly improve the residents’ and students’ knowledge about endemic fluorosis.Defluoridation stove can be used to reduce the concentration of fluoride in indoor air.