利用1∶25万贵州省多目标区域地球化学调查（贵阳中心区）成果，采用单因子和尼梅罗综合指数法对贵阳中心区表层土壤（0—20 cm）重金属污染及其环境影响进行评价和研究．结果表明，重金属污染程度依次为Cd＞As＞Hg＞Zn＞Ni＞Cu＞Cr＞Pb．As、Cd、Hg、Zn等元素出现污染，其中Cd最重，污染区占总面积的6．15％，且72％的土壤为警戒区，其次是As，污染区占5．31％，Hg、Zn主要为轻微点状污染，Cr、Cu、Ni、Pb等元素土壤环境质量以清洁和安全区为主，未对土壤造成污染．尼梅罗综合污染指数为0．58—26．72，平均值2．27，表明研究区土壤整体污染已达警戒级别，且区域内污染程度变化范围较大；贵阳中心区表层土壤重金属污染比较严重，清洁区仅占总面积的3．5％，安全区占48．6％，警戒区占32．9％，污染区占15％，近50％土壤不适宜种植农作物．生态环境影响调查结果表明，土壤重金属元素异常区农作物已遭到一定程度的重金属污染，地下水也存在Pb2＋超标现象．
Based on the monitoring results of multi-target regional geochemical survey of Guizhou province ( central district of Guiyang ) ( 1∶ 250000 ) , the soil heavy metal pollution and its environmental impacts were evaluated by single factor and Nemero comprehensive index methods in the central district of Guiyang. The results show that the pollution level of heavy metal decreases in the order of Cd>As>Hg>Zn>Ni>Cu>Cr>Pb. The elements such as As, Cd, Hg and Zn are all in the pollution state. The pollution level of Cd element has the largest polluted area, which reached 6.15%, and the warning area of Cd pollution reached 72%.The pollution level of As element has the second largest polluted area, which reached 5. 31%. The pollution level of Hg, Zn elements are minor point pollution, and the other elements such as Cr, Cu, Ni, and Pb have not resulted in pollution of soils. The Nemero comprehensive pollution index of the survey region is in the range of
0.58—26.72, and its average value is 2. 27, which shows that the integrated pollution degree has reached the warning level. Heavy metal pollution level of the survey region is relatively serious, the clean area accounted for only 3.5% of the total area, the safety area accounted for about 48.6%, the warning area accounted for about 32. 9%, the polluted area accounted for about 15%, and nearly 50% of the soil is not suitable for growing crops. The survey results of ecology and environment impacts show the crops have been a certain degree of heavy metal pollution,and groundwater Pb2+also has exceeded the national standard in soil anomalies areas of heavy metal elements.
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