贵州遵义农业区域土壤中重金属环境化学背景研究

Environmental Geochemical Background Study of Heavy Metals in Soils in Zunyi Ag-ricultural Region of Guizhou

摘要: 应用环境化地球学基线研究方法，识别区域尺度自然作用过程与人类活动影响，通过889个样品分析，表明该区域基线值分别为Hg：0.090；Cd：0.147；Pb：20.39；Cr：42.78；As：6.54 (mg/kg)。地质累积指数分析结果显示：1) Hg 24.07%为1级，60.74%为2级；2) Cd 13.84%为1级，80.54%为2级；3) Pb 46.42%为1级，43.97%为2级；4) Cr74.58%为1级，24.41%为2级；5) As 40.16%为1级，47.13%为2级。应用潜在生态危险分析，Hg大约有85%，Cd有70%，Pb、Cr、As三种元素有90%为1级和2级。应用地质累积频率法和潜在生态风险法估算，二者污染的趋势和污染程度结果一致。

Abstract: The environmental chemistry baseline research method was used to identify the natural process and anthropogenic influence at the regional scale. Statistical analysis of heavy metals in 889 sam-ples illustrated the baseline value of Hg, Cd, Pb, Cr, and As was 0.090 mg/kg, 0.147 mg/kg, 20.39 mg/kg, 42.78 mg/kg and 6.54 mg/kg respectively. The results of geoaccumulation index show that 1) class 1 accounts for 24.07% and class 2 accounts for 60.74% for Hg; 2) class 1 accounts for 13.84% and class 2 accounts for 80.54% for Cd; 3) class 1 accounts for 46.42% and class 2 accounts for 43.97% for Pb; 4) class 1 accounts for 74.58% and class 2 accounts for 24.41% for Cr; 5) class 1 accounts for40.16% and class 2 accounts for 47.13% for As. Meanwhile, the results of potential ecological risk assessment show a low risk of Hg, Cd, Pb, Cr and As accounting for 85%, 70%, 90%, 90% and 90%, respectively. The results showed that the regional soil environmental chemical background in Zunyi area by the methods of geoaccumulation frequency is consistent with the result of potential ecological risk assessment.