广东省土壤硒空间分布及潜在环境风险分析

利用广东省260个土壤剖面数据,开展区域尺度下的土壤总硒（Se）质量分数的空间分布研究。结果表明,研究区内土壤硒含量变异性较强,符合对数正态分布特征,其几何质量分数为0.23 mg·kg-1,高于全国平均水平。表层土壤硒基线质量分数范围为0.13到0.41 mg·kg-1,处于硒缺乏与中等含量水平之间。土壤硒的空间分布格局与区域成土母质密切相关,表现为：高硒质量分数的土壤主要位于石灰岩和砂页岩区域,而低硒质量分数的土壤主要位于紫色页岩和花岗岩地区。土壤硒缺乏可能是影响研究区人体健康的重要问题。此外,研究区由土壤退化和土壤侵蚀引发的流入周边水体的土壤硒每年可高达23 t。

Spatial variation and environmental indications of soil selenium in Guangdong province

A total of 260 soil profiles were examined to investigate the spatial distribution of total soil selenium（Se） in Guangdong province,China.The soil Se concentrations follow an approximately lognormal distribution.The soil Se geometric mean concentration of 0.23 mg·kg 1is higher than that of Chinese soils;However,Se concentration varies over the study area.The baseline concentration of 0.13 to 0.41 mg·kg 1 indicates that the soil Se concentration is mostly in the range of deficiency to medium level for surface soils in Guangdong province.In A-,B-,and C-horizon,soil Se spatial distribution is correlated with the nature of the parent material,with high Se concentration mainly located in limestone and sandshale areas and low Se concentration associated with purple shale and granite areas.The present result suggests that potential Se deficiency may be an issue for human health in this province.Moreover,due to soil degradation and erosion,calculated soil Se exported into surrounding waters could reach approximately 23 t.a 1in the study area.