陕西南部大巴山区碘的分布规律与克汀病

Distributing Pattern of Iodine and Endemic Cretinism in Daba Mountains (South Qinling Mountains),South Shaanxi Province

通过对陕西南部大巴山地区的基岩、土壤、作物、泉水及地表水中含碘量和分布规律的研究 ,发现本区环境中碘的分布很不均衡 ,变化较大 ,包括从极低碘到高碘的多种情况 .本区主要分布的早古生代地层均富碘 ,岩石的含碘量为 0 .7～ 1 .9mg/kg .在山坡坡度较缓的基性火成岩分布区的基岩、土壤、作物均富碘 ,一般为 1 .4～ 0 .9mg/kg .土壤的含碘量为 0 .2～ 2 .2mg/kg ;土豆的含碘量为 8～ 1 80 μg/kg .由于长期的风化剥蚀 ,大巴山区大多数地区的土壤和作物缺碘 ,特别是碳酸盐岩分布区以及高大山头上部的土壤和作物均缺碘 .土壤和作物中含碘量与其分布区的基岩的岩性和含碘量以及地理环境密切相关 ,同时本区克汀病的分布和发病率与环境中碘的含量和分布也密切相关 .

The iodine content and distributing pattern in the bedrock,soil,crop,spring and main rivers of Daba Mountains (South Qinling Mountains) region were studied. The result shows that iodine content in this region is not balanced and most area is short of iodine,specifically in the distributing area of limestone and sandstone as well as the upper part of big hill.The iodine content in the bedrock,which are mainly early Paleozoic strata,is high,it is about 0.7～1.9 mg/?kg,among them,the igneous rock,specifically the diabase is more rich in iodine,it is about 1.4～1.9 mg/?kg. The iodine content of soil is 0.2～2.2mg/?kg;the iodine content of potato is 8～180μg/?kg. The iodine content of the soil and crop that is distributing in the area of igneous rock is rich in iodine if the hill is not more steep and cranny is not developed. The iodine content of the soil and crop that is in the distributing area of sandstone and limestone is the lowest in this region. So,the iodine content in the soil,crop and spring is closely related with the iodine content and lithologic character of the bedrock and geographical condition in these region and simultaneously closely related with the distributing pattern of the cretinism in the region. \ \