温州市居民生活饮用水碘空间分布特征

Spatial distribution of iodine in drinking water in Wenzhou

目的了解温州市居民生活饮用水碘空间分布特征,为防制碘缺乏病提供依据。方法按照供水方式不同对温州市11个县(市、区) 182个乡(镇、街道)居民生活饮用水进行抽样调查,采用硫酸铈催化分光光度法测定水碘含量。采用Arc GIS 10.2软件建立空间数据库和绘制地图,采用Geo Da 1.10软件进行空间自相关分析,采用Sa TScan 9.4软件进行空间扫描分析。结果采集生活饮用水样1 008份,水碘含量≤10.00μg/L 998份,占99.01%,以乡(镇、街道)为单位的水碘中位数为1.80μg/L。地理空间分布显示,温州市居民生活饮用水碘全局分布存在正空间自相关性(Moran's I=0.40,Z=15.65,P<0.05);78个乡(镇、街道)居民饮用水水碘局部存在4种空间聚集模式(P<0.05);空间扫描探测出3个聚集区,高水碘第一聚集区在洞头区3个乡(镇、街道),高水碘第二聚集区在苍南县7个沿海乡(镇、街道),低水碘聚集区包括49个乡(镇、街道),在永嘉县、乐清市及鹿城区。结论温州市属于低水碘地区,水碘分布存在空间聚集性。

Objective To understand the spatial distribution of iodine in drinking water in Wenzhou,and to provide reference for preventing iodine deficiency disorders. Methods Drinking water was sampled from 182 townships of all 11 counties under the jurisdiction of Wenzhou according to different ways of water supply. The iodine in water was detected by cerium sulfate catalytic spectrophotometry. The water iodine data was matched with the electronic map by Arc GIS10.2 to construct a spatial database;spatial autocorrelation analysis by Geo Da1.10 and spatial scanning analysis by Sa TScan 9.4 were conducted to obtain the water iodine concentration range in Wenzhou. Results The contents of iodine in 998 out of 1 008 drinking water samples were less than 10 μg/L,accounting for 99.01%. The median of water iodine in all townships of Wenzhou was 1.8 μg/L. The results of geospatial distribution analysis demonstrated that the iodine distribution in drinking water had positive spatial autocorrelation in Wenzhou(Moran’s I= 0.40,Z=15.65,P<0.05);there were four kinds of local aggregation models for water iodine in 78 townships(P<0.01). Three cluster areas of the water iodine were detected by space scanning,with three townships in Dongtou as the first high cluster areas,seven coastal townships in Cangnan as the second high cluster areas and 49 mountainous townships in Yongjia,Yueqing and Lucheng as the low cluster areas. Conclusion The iodine in drinking water in Wenzhou was low and exists spatial aggregation.