山东省浅层地下水碘化物含量与甲状腺癌发病人数空间关系初探

Preliminary Study on the Spatial Distribution of Iodide in Shallow Groundwater and the Incidence of Thyroid Cancer in Shandong

目的掌握山东省浅层地下水碘化物含量的空间分布特征,探究浅层地下水碘化物含量与甲状腺癌的关系,为地方性疾病的预防和碘盐长期供应普适性的研究提供依据。方法利用地统计与地理信息技术相结合的方法,以实际采样点为参考进行空间变异拟合,再通过普通克里金插值得到全省浅层地下水碘化物含量的空间分布;地理信息系统(Geographic Information System,简称GIS)空间叠加的方法直观展示浅层地下水碘化物含量与甲状腺癌患者的空间集聚关系,在对栅格化后的空间插值结果进行地理空间分区的基础上,利用统计学原理,求平均、数理统计、建立回归分析等,得到最适宜于研究两者之间关系的模型,利用统计产品与服务解决方案(Statistical Product and Service Solutions,简称SPSS),以碘化物含量为自变量,甲状腺癌患者的数目为因变量,进行相关性分析、建立散点图和函数模型,比较参数。结果山东省浅层地下水碘化物含量由西部的高碘区逐渐过渡到东部的适碘区;且碘化物含量分布与甲状腺癌患者分布情况趋于一致。含量高的区域,患者分布密集;碘化物含量与患者数量的相关性因子为0.816。结论浅层地下水碘化物含量在50μg/L以上的情况下,含量越高病患分布越为密集,浅层地下水碘化物含量与甲状腺癌具有很强的相关性。

Objectives To know well the spatial distribution of Iodide content in shallow groundwater in Shandong province,and to explore the relationship between iodide content in shallow groundwater and thyroid cancer,and to supply research bases for the prevention of endemic diseases and long-term supply of iodized salt. Methods Combining geostatistics and geographic information technology,fitting spatial variability with actual sample points reference,then using the ordinary Kriging interpolation to get the distribution of iodide contents in shallow groundwater in space. The method of spatial overlay in GIS is used to intuitively show the relationship between iodide in shallow groundwater and spatial aggregation of patients with thyroid cancer. Based on the spatial partition of the spatial interpolation result,the most suitable model to study the relationship between them was discovered,after rasterization by using statistical principle,seeking average,carrying out mathematical statistics,setting up regression analysis etc. Use SPSS to carry on the correlation analysis,establish scatter plot and function model with iodide content as the independent variable,the number of patients with thyroid cancer as dependent variable,and compare parameters. Results Iodide content of shallow groundwater in Shandong varies from the high iodide area in the west to the suitable iodide region in the east. The distribution of iodide content is consistent with the distribution of thyroid cancer patients： patient distribution is intensive in the high content area,the correlation factor between iodide content and the number of patients is 0.816. Conclusions When the iodide content in shallow groundwater is above 50 μg/L,the higher the content become the more intensive the patient distribution is,which is strongly correlated with thyroid cancer.