化州市水源性高碘地区分布及其流行病学调查分析

Investigation on distribution of high water iodine region and its epidemiology in Huazhou

目的为掌握化州市高水碘分布情况,划定水源性高碘村范围,开展高水碘对居民碘营养水平的安全性评估,制订有效的预防控制措施提供依据。方法首先采用横断面筛查方法,根据鉴江干流和支流的走向、地理位置等情况,将化州市全部镇(街)分重点调查镇和一般调查镇,筛查各镇自然村居民饮水碘含量;筛查发现碘含量>100μg/L的水样,则在水样采集的自然村按10%比例进行扩大抽样以确定水源性高碘地区;在水源性高碘村开展居民尿碘、盐碘和6~12岁儿童甲状腺肿大率的流行病学调查,并随机抽查部分村居民饮用桶装水情况;水碘检测采用电感耦合等离子体质谱仪法(ICP-MS),尿碘检测按《尿中碘的砷铈催化分光光度测定方法》,甲状腺肿大用触诊法检查,盐碘含量检测采用《制盐工业通用试验方法碘的测定》。结果全市水碘中位数为20.0μg/L,共发现水碘含量>:100.1μg/L的水样共115份,全是地下井水,一个自然村范围内地下水碘含量高、中、低3种浓度交叉并存;有7个自然村可判定为水源性高碘地区,3个村水碘中位数在100.1μg/L^150μg/L之间;上述村居民尿碘中位数在133.0μg/L^381.2μg/L之间,各村的井水碘含量中位数和居民尿碘中位数水平无相关性;各村的6~12岁儿童甲状腺肿大率均较低,碘盐覆盖率在80.6%~100.0%范围,抽查村居民家庭饮用桶装水比例均较高。结论化州市水源性高碘村在鉴江流域地区呈小范围、散点状分布,尚未发现地方性高碘甲状腺肿病区;通过居民尿碘频数分布、碘盐覆盖率和饮用桶装水情况综合分析,建议采取以地表水为水源的改水降碘防控措施。

Objective To master the present conditions of excess iodine and its epidemiology in Huazhou,delimit high water iodine region and carry out the safety evaluation of high water iodine on the nutrition level of residents,for providing the evidence for control.Methods Across section was adopted for the epidemiological survey in all of townships.Two to five samples of drinking water at each village were tested for water iodine content.10%proportion of drinking water was tested again at the village whose water samples with the proportion of more than 100 μg/L in iodine content in order to delimit high water iodine region.Urine iodine,iodized salt and thyroid condition of children at the age from six to twelve were tested in the village with high water iodine as well as the data regarding to drinking barreled water.ICP-MS was adopted in the test of water iodine,urine iodine determination of arsenic cerium catalytic spectrophotometric method was adopted in the test of urine iodine level,the palpation was adopted in the test of thyroid goitre rate.Result The median water iodine in the whole city was 20.0 μg/L.There were 115 samples of drinking water all from the well in which values of iodine content were 〉100.1 μg/L.High iodine content,medium iodine and low iodine were coexisted in the underground water of one village.There were seven villages which were judged as high level water iodine regions,three villages in which the median water iodine was 100.1 μg/L-150 μg/L,the urinary median iodine was133.0 μg/L-381.2 μg/L of residents at these villages.There was no relativity between the median well water iodine and the urinary median iodine of residents at each village/The thyroid goitre rate of children at the age from six to twelve was low.The rate of iodized salt was 80.6%-100.0%.Conclusion High water iodine regions were dotted-scattered in Huazhou.There was no thyroid goitre area.To drink surface water which was as a source of drinking water might be the best measure of reducing high water iodine according to general analysis of urine iodine frequency distribution,the rate of iodized salt and the proportion of drinking barreled water.