摘要目的 了解天津市饮水型氟中毒病区不同改水方式和改水年限对儿童氟斑牙的影响,为进一步改水降氟提供科学依据.方法 2016、2017年,在天津市全部涉农区采用单纯随机抽样的方法 抽取1/4的病区村开展改水情况调查,改水方式包括市政管网、双管网、桶装水、低氟井和集中联片5种,改水年限分别为＞ 15、＞10～15、5～ 10、＜5年.采集821份水样,包括地面水、桶装出厂水、地下水,使用氟离子选择电极法检测水氟含量,按照《氟斑牙诊断》(WS/T 208-2011)标准,在病区村检查8～12周岁儿童氟斑牙患病情况.结果 共调查天津市524个饮水型氟中毒病区村,改水率为73.28％(384/524),水氟合格村占53.24％(279/524);共调查35 870名8～ 12周岁儿童,儿童氟斑牙检出率为47.98％(17 209/35 870).不同改水方式地区,儿童氟斑牙检出率比较差异有统计学意义(x2=1 955.742,P＜0.05).其中市政管网工程改水地区儿童氟斑牙检出率较低(33.19％,4 121/12416);双管网工程改水地区儿童氟斑牙检出率为43.37％(995/2 294);桶装水、低氟井和集中联片工程改水地区儿童氟斑牙检出率较高(58.47％,6 268/10 720;66.84％,1 719/2 572;53.75％,623/1 159).市政管网工程改水地区水氟中位数为0.24 mg/L,水氟≤1.2 mg/L的村所占比例为100.00％(133/133),且改水年限＞15、＞10～15年的儿童氟斑牙检出率分别为17.41％(428/2 459)、14.19％(266/1 875)达到控制标准(≤30％).结论 天津市市政管网改水方式最彻底,尤以改水年限＞10年效果最佳,能达到持续保障病区居民饮用水安全的要求,其他改水形式需进一步优化.

abstractsObjective To investigate the influence of different water-improving defluoridation projects and different water-improving years on children's dental fluorosis,and to provide a scientific basis for further defluoridation of drinking water.Methods Totally 1/4 endemic fluorosis villages in all agricultural-related areas of Tianjin were selected by random sampling method from 2016 to 2017.The situation of water-improving defluoridation project was investigated in these villages.The ways of water improvement included municipal water supply,double pipe network,barreled water,low fluorine well and centralized water supply.The years of water improvement were ＞ 15,＞ 10-15,5-10,and ＜ 5 years,respectively.Totally 821 water samples (surface water,barreled water and groundwater) were collected.Fluoride ion selective electrode method was used for determination of water fluorine content.According to the "Diagnosis of Dental Fluorosis" (WS/T 208-2011),the prevalence of dental fluorosis in children aged 8 to 12 was examined.Results A total of 524 villages with drinking water endemic fluorosis and 35 870 children aged 8 to 12 were investigated in Tianjin.The water improvement rate was 73.28％ (384/524).Water fluoride qualified village accounted for 53.24％ (279/524).The detection rate of dental fluorosis was 47.98％ (17 209/35 870),the detection rate of dental fluorosis was different with different water improvement methods (x2 =1 955.742,P ＜ 0.05).Children's dental fluorosis detection rate in the area of municipal water supply was lower (33.19％,4 121/12 416),while that in double pipe network reconstruction area was 43.37％ (995/2 294).Children's dental fluorosis detection rates in the areas of barreled water supply,low fluoride well and centralized water supply were higher (58.47％,6 268/10 720;66.84％,1 719/2 572;53.75％,623/1 159).The median of water fluoride in the renovated area of municipal water supply was 0.24 mg/L,and the proportion of villages with water fluoride ≤ 1.2 mg/L was 100.00％ (133/133).With the increase in water-improving years (more than 10 years),children's dental fluorosis prevalence [＞ 15,＞ 10 ～ 15 years were 17.41％ (428/2 459),14.19％ (266/1 875)] in the areas of municipal water supply reached the control standards (≤30％).Conclusions The improvement of the municipal water supply network is thorough,which can meet the requirement of continuously ensuring the safety of drinking water for residents,especially those over 10 years.Other forms of water-improving need to be further optimized.