冀东表层土壤中镉的环境地球化学基线

以土壤环境地球化学研究为主线,以冀东地区13 472 km2为研究区域,将土壤重金属污染元素镉的空间分布规律与环境地球化学机理研究相结合,建立区域土壤环境地球化学基线,选用合适的判别指标判识自然作用过程与人类活动过程对土壤环境的影响。通过对3 287个样品的镉含量的统计分析,结果表明,冀东地区表层土壤中镉的基线值为0.073 mg/kg,镉元素含量大于0.230 mg/kg的样品可能遭受人为污染的影响。地质累积指数分析结果显示,冀东地区49.0%的表层土壤未受镉污染,47.6%的表层土壤在无污染与中度污染之间,2.1%受中度污染,1.2%的表层土壤介于中度污染到强污染之间,只有1%受强污染。污染程度指数分析则显示,冀东地区94.5%的表层土壤未受到镉污染,98.8%的表层土壤污染程度小于2,总污染程度小于0,即总体未受到污染。

Geogenic Distribution and Baseline Concentrations of Cadmium in Surficial Soil from Eastern Hebei Province,China

The characteristics of environmental geochemistry of heavy metal pollutant cadmium(Cd) in the surficial soil from Eastern Hebei Province about 13,472 km2 were studied.The baseline concentration of Cd in soil and the geochemistry norms have been established to distinguish the nature or artificial influence on the environment.The statistical analysis indicated that the baseline of Cd from Eastern Hebei Province was 0.073 mg/kg.Geoaccumulation index analysis indicated that the unpolluted surface soil accounts for 49.0%,and 47.6% between nonpollution and mid-pollution,2.1% for mid-pollution,1.2% between mid-pollution and severe pollution,only 1% for severe pollution.The maximum of Cd contamination degree(CD) is 8.9.CD analysis indicated that the unpolluted surface soil accounts for 94.5%.The total CD below zero in surficial soil of Eastern Hebei Province does not suffer from cadmium pollution.