长三角典型地区土壤环境中Se的空间变异特征及其与人类健康的关系

农业土壤环境中硒（Se）的缺乏或过量都会通过食物链最终影响人类健康。在203个土壤采样点的基础上，利用GIS和地统计学相结合的方法，对江苏省如皋市农田土壤环境中Se的空间变异特征及其影响因素进行分析，同时，对土壤中Se的空间分布与长寿人口的空间分布进行空间叠加分析。研究结果表明，如皋市土壤环境中总Se及水溶态Se的平均含量分别为0.13 mg/kg和2.16 μg/kg，研究区处在相对低Se的土壤环境中。总Se的空间变异性不大，其空间分布比较均一；但水溶态Se的空间变异性较大，主要受成土条件及土壤母质、土壤类型及地形地貌等结构性因子的影响。水溶态Se对土壤的理化性质也比较敏感，特别是速效磷、有机质及全钾含量与水溶态硒的相关性较显著，因此在有机质及土壤养分含量较高、土壤颗粒组成较细的东部及北部地区水溶态硒的含量也较高。土壤水溶态Se的空间分异与长寿人口比率的空间分异呈极显著的正相关关系(〖WTBX〗P〖WTBZ〗<001)，相关系数达〖WTBX〗r〖WTBZ〗=0325，表明人类的健康长寿现象与环境中水溶态硒的含量有很大关系，但人类长寿的本质和真正机理仍需进一步研究验证。

SPATIAL VARIABILITY OF SELENIUM IN SOIL ENVIRONMENT AND ITS CORRELATION WITH HUMAN HEALTH IN THE YANGTZE RIVER DELTA OF CHINA

Selenium (Se) deficiency or excess in agricultural environment can induce some endemic disease or health risk through food chains.In this paper，the spatial variability and the driving factors of Se in soil environment were studied with the help of GIS and Geostatistics based on 203 soil samples in Rugao County，Jiangsu Province.Meanwhile，the correlations between the spatial distribution of longevity ratio and water soluble Se in topsoil were discussed.The results indicated that the study area is in the low Se soil environment，the average of total Se and water soluble Se in topsoil is 013 and 242 μg/kg respectively.Water soluble Se in the environment might be an advantageous contributor to the bioavailability，flux in food chains and human health.It is more sensitive to soil physicochemical properties especially available P，soil organic matter and total K，so the spatial distribution of water soluble Se is higher in the east and north parts of the county.A very significant (〖WTBX〗P〖WTBZ〗<001) correlation between water soluble Se in topsoil and the longevity ratio suggests that water soluble Se in soil environment has significant effect on the longevity of human beings.However，the essential mechanism of the longevity in human beings is expecting for further study.