兰州市不同水源地区水碘含量调查分析

Investigation and analysis of water iodine content in different water source areas in Lanzhou city

目的掌握兰州市不同水源地区水碘含量的范围与分布,为制订适合的防控措施提供科学依据。方法采样的各县(市、区)按照供水的水源类型、规模大小并结合供水人口等进行分层,按分层随机原则选择抽样点。采用适合缺碘及高碘地区的水碘检测方法(国家碘缺乏病参照实验室推荐方法)进行水碘含量测定。结果共采集876份水样,其中出厂水水样280份(140个集中式供水工程),末梢水水样596份。140个集中式供水工程出厂水水碘范围为0.2-74.5μg/L,中位数1.92μg/L,水碘含量<10μg/L、10-30μg/L、30-50μg/L、50-70μg/L和≥70μg/L的比例为88.6%、6.4%、2.1%、1.4%和1.4%;地面水和地下水比例为22.1%和77.9%,中位数为1.31μg/L和2.14μg/L,地面水水碘<地下水水碘(Z=-2.759,P<0.01);地下水浅井水、深井水和泉水比例为22.9%、45.9%和31.2%,水碘中位数为1.88μg/L、3.18μg/L和1.63μg/L,3组水碘含量差异有统计学意义(χ~2=11.8,P<0.01)。596份末梢水水样水碘范围为0.2-65.2μg/L,中位数2.20μg/L,水碘含量<10μg/L、10-30μg/L、30-50μg/L和≥50μg/L的比例为92.1%、7.0%、0.3%和0.5%,各县(市、区)水碘含量差异有统计学意义(χ~2=39.86,P<0.01);末梢水中集中供水73份,分散供水523份,水碘中位数分别为2.20μg/L和2.05μg/L,水碘含量差异无统计学意义(Z=-0.436,P>0.05)。结论兰州市生活饮用水水源类型多,水碘含量普遍较低,地面水水碘含量低于地下水,地下水中深井水水碘含量高于浅井水和泉水,各水源类型和各县(市、区)生活饮用水水碘含量中位数均<10μg/L,兰州市仍处于外环境缺碘地区。

Objective To grasp the scope and distribution of water iodine content in different water source areas,and provides a basis for taking appropriate control measures in Lanzhou.Methods According to the type of water source,the size and population of the water supply,the counties shall select sampling points according to the principle of stratified random principle. The source water iodine by the method suitable for iodine deficiency and high iodine areas（ recommended method of reference laboratory of the national iodine deficiency disorders） in Lanzhou.Result Total 876 water samples including 280 water samples of 140 centralized water-supply projects and 596 table water samples.The water samples of centralized water-supply projects,the median of water iodine was 1.92 μg/L,the rates were 88.6%,6.4%,2.1%,1.4% and 1.4% in water iodine level of 10 μg/L,10 ~ 30 μg/L,30 ~50 μg/L,50 ~ 70 μg/L and ≥70 μg/L,respectively.The surface water was 22.1%, the median of water iodine was 1.31 μg/L,the groundwater was 77.9%,the median of water iodine 2.14 μg/L,the iodine content of surface water was lower than the groundwater（ Z =-2.759,P0.01）; In the groundwater, the rate of shallow well,deep well and spring was 22.9%,45.9% and 31.2%,and the median was 1.88 μg/L,3.18 μg/L and 1.63 μg/L,difference between the three groups has statistical significance（ χ^2=11.8,P0.01）.The 596 table water samples, the median of water iodine was 2.20 μg/L,the rates were 92.1%,7.0%,0.3% and0.5% in water iodine level of 10 μg/L,10 ~ 30 μg/L,30 ~ 50 μg/L and ≥50 μg/L, difference between the counties in Lanzhou has statistical significance（ χ~2= 39. 86,P 0. 01）. There were 73 centralized water-supply samples and 523 decentralized water-supply samples in the table water, the median of water iodine was 2.20 μg/L and 2.05 μg/L,difference between the two groups has statiscal significance（ Z =-0.436,P〈 0. 05）. Conclusion Iodine content of the surface water is generally lower than that of other types in Lanzhou,the iodine content of deep well is higher than that of shallow well and spring,the median of water iodine is lower than 10 μg/L in all the types of source water and all the counties.Lanzhou city is still an iodine deficiency area in external environment.