中文摘要：

自20世纪末实施全面加碘盐以消除碘缺乏病政策以来,我国碘缺乏病状况得到了极大改善,但高碘致病问题也引起了越来越多的关注和讨论.基于4 136组饮用地下水碘数据分析了华北平原饮用地下水碘的空间分布及其水文地质效应,并基于流行病学提出了饮用水合理碘含量限值的建议,据此将华北平原划分为极缺碘水区（≤4 μg·L-1）、缺碘水区（＞4～8μg·L-1）、适碘水区（＞8～50 μg·L-1）、可饮用碘水区（＞50～100 μg·L-1）、高碘水区（100～200 μg·L-1）和超高碘水区（＞200 μg·L-1）.针对不同分区计算了食盐的合理加碘量,并从饮用水碘含量的角度将华北平原划分为需用加碘盐区、不需加碘盐区和不宜加碘盐区,这对于指导该区加碘盐政策的科学优化、解决食盐加碘带来的负面影响具有科学指导意义.研究发现,受水文地质条件和地下水循环特征控制,缺碘饮用地下水主要分布在燕山—太行山山前冲洪积平原及黄河冲洪积平原濮阳段,尤其近山的冲洪积平原是极缺碘饮用地下水的分布区;高碘地下水则主要分布在黄河冲洪积平原、东部滨海平原.计算结果表明,极缺碘水区与缺碘水区为需用加碘盐区,目前使用的20～ 50 μg·g-1加碘盐能满足人体碘需求;适碘水和可饮用碘水区为不需加碘盐区,食盐碘含量应不大于9.2 μg·g-1;高碘水和超高碘水区为不宜加碘盐区,建议仅供应无碘盐.

英文摘要：

The incidence of iodine deficiency disorder in China has been greatly reduced since the promotion of iodized salt in late 1990s, however, the issue of excess iodine causing disorder is also attracting more and more concerns. A total of 4 136 groups of water samples were collected from both shallow and deep underground drinking water sources in the North China Plain for analysis of iodine content to explore spatial distribution of iodine in groundwater and its hydrogeologi- cal effect. And based on the epidemiology, a reasonable iodine content in drinking water was put forward. On such a basis, the North China Plain was divided into six regions, namely, extremely iodine-deficient region （ 〈4 μg· L-1） , iodine-de- ficient region （〉4-8μg· L-1）, iodine-proper region （〉8-50μg·L-1）, drinkable high iodine region （〉50-100μg· L-1）, high iodine region （〉100-200 μg· L-1） and extremely high iodine region （〉200μg· L-1）. A proper iodine a- mendment rate in salt was worked out for each region. And based on iodine contents in groundwater, the plain could be di- vided into three regions, namely, iodine required region, iodine unrequired region and iodine-amendment unfit region. Such divisions are of some scientific significance for guiding optimization of salt iodization and solution of the problem of negative impact of the salt iodization. Results indicate that iodine-deficient groundwater is mainly distributed in the pedi- ment alluvial-diluvial plain of the Yanshan Mountains-Taihang Mountains and the Puyang section of the Yellow River allu- vial-diluvial plain; extremely iodine-deficient groundwater in the alluvial-diluvial plains adjacent to the mountains; and high iodine groundwater in the Yellow River alluvial-diluvial plain and the eastern coastal plain. The calculation shows that addition of iodine is required to the table salt for the extremely iodine-deficient regions and iodine-deficient regions, wherethe currently used 20-50 μg· g-1 iodized salt is adequate to meet the