2012-2017年山西省太原市水源性高碘地区监测结果分析

Analysis of monitoring results in water source high iodine areas in Taiyuan City,Shanxi Province from 2012 to 2017

目的了解山西省太原市水源性高碘地区停供碘盐情况,水碘含量及儿童碘营养状况,为高碘地区因地制宜地实施防治措施提供依据。方法2012-2017年,在太原市水源性高碘地区(清徐县和小店区)的全部高碘乡,每个高碘乡抽取4个行政村,每个行政村抽检15户居民食用盐,采用半定量法检测盐碘。按照《全国水源性高碘地区监测方案(试行)》(2012版),每年在清徐县和小店区分别选取1~2个高碘村作为监测点,并按水碘150~300μg/L和>300μg/L进行分组。如监测点已改水,采集1份末梢水水样;如监测点尚未改水,则按照东、西、南、北、中5个方位各采集2户居民饮用水水样,采用中国疾病预防控制中心国家碘缺乏病参照实验室推荐的“适合缺碘及高碘地区水碘检测的方法研究”检测水碘。在监测点所在村小学或乡镇中心小学,抽取100名8~10岁儿童,采用B超法检测甲状腺容积;采集其中≥30名儿童尿样,采用砷铈催化分光光度法检测尿碘。结果2012-2017年,清徐县未加碘食盐率范围为91.7%(165/180)~96.1%(173/180);小店区未加碘食盐率均为100.0%(120/120)。共检测水样52份,水碘中位数为282.3μg/L,范围为121.1~546.3μg/L。共检查1401名儿童甲状腺,甲状腺肿大率为7.5%(105/1401)。共检测儿童尿样597份,尿碘中位数为458.1μg/L,范围为21.0~1778.7μg/L。水碘为150~300μg/L组儿童尿碘中位数(327.1μg/L)、甲状腺肿大率(4.9%,34/697)与水碘>300μg/L组(552.9μg/L;10.1%,71/704)比较,差异有统计学意义(Z=-8.934,χ^2=13.698,P均<0.01)。结论2012-2017年太原市水源性高碘地区水碘中位数为282.3μg/L,停供碘盐情况良好(未加碘食盐率均>90%);但儿童碘营养过量(尿碘中位数≥300μg/L),且甲状腺肿大率超标(>5%)。建议水源性高碘地区应以改水降碘为主要措施,持续对生活饮用水碘含量进行监测,根据水碘变化及时调整防治措施。

Objective To investigate the status of removing iodized salt,water iodine,and iodine nutrition of children in water source high iodine areas in Taiyuan City,Shanxi Province,so as to provide basis for the implementation of prevention and control measures in high iodine areas according to local conditions.Methods From 2012 to 2017,four administrative villages were selected from each of the high iodine townships in the water source high iodine areas(Qingxu County and Xiaodian District)in Taiyuan City,and 15 households in each administrative village were sampled for salt iodine detection by semi quantitative method.According to the"National Monitoring Program for Water Source High Iodine Areas(Trial)"(2012 edition),1-2 high iodine villages were selected respectively in Qingxu County and Xiaodian District every year as monitoring sites,and grouped by water iodine of 150-300μg/L and>300μg/L.If the monitoring site had been implemented the water improvement project,one tap water sample shall be collected.Whereas,if the monitoring site had not been implemented the water improvement project,two drinking water samples shall be collected from each household in the five directions of east,west,south,north and middle,and the water iodine shall be detected using the"Research on Methods for Water Iodine Testing in Iodine Deficiency and High Iodine Areas"recommended by the National Iodine Deficiency Disorders Reference Laboratory of the Chinese Center for Disease Control and Prevention.A total of 100 children aged 8-10 years old were selected from village primary schools or central primary schools in townships where the monitoring sites were located,and their thyroid volume was detected by B-ultrasound;urine samples were taken from more than 30 children and urinary iodine was detected by arsenic-cerium catalytic spectrophotometry.Results From 2012 to 2017,the rate of non-iodized salt in Qingxu County ranged from 91.7%(165/180)to 96.1%(173/180);the rate of non-iodized salt in Xiaodian District were all 100.0%(120/120).A total of 52 water samples were tested,and the median water iodine was 282.3μg/L,ranged from 121.1 to 546.3μg/L.A total of 1401 children's thyroid were examined,and the goiter rate was 7.5%(105/1401).A total of 597 children's urine samples were tested,and the median urinary iodine was 458.1μg/L,ranged from 21.0 to 1778.7μg/L.The median urinary iodine(327.1μg/L)and goiter rate(4.9%,34/697)of children in the 150-300μg/L water iodine group were compared with those in the>300μg/L water iodine group(552.9μg/L;10.1%,71/704),the differences were statistically significant(Z=-8.934,χ^2=13.698,P<0.01).Conclusions From 2012 to 2017,the median water iodine is 282.3μg/L in water source high iodine areas in Taiyuan City,the status of removing iodized salt is good(the rate of non-iodized salt>90%).However,children have excessive iodine(median urinary iodine 5=300μg/L)and goiter rate(>5%).It is suggested that the main measures should be taken to improve water quality and reduce iodine content in drinking water in water source high iodine areas,continuously monitor water iodine,and timely adjust the prevention and control measures according to the change of water iodine.