新产区土壤和三七中重金属元素的累积状况

Accumulation of Heavy Metal Elements in Soil and Panax Notoginseng in New Producing Areas

云南是重金属元素的高背景区,也是三七的主产区,近年来有关中药材中重金属累积污染的问题倍受关注,但是由于连作障碍的原因,三七种植区已从传统地道产区文山向外扩散,笔者以红河州三七种植区为研究对象,研究了红河州四个市县三七种植区土壤和三七中四种重金属元素的累积状况。结果表明:(1)目前红河州三七种植区土壤Cd含量范围0.113~1.01 mg/kg,As含量范围5.34~220.2 mg/kg,Cu含量范围30.6~143 mg/kg,平均值分别为0.48、53.17、58.30 mg/kg,有多个采样点存在超标现象。(2)通过综合污染指数发现,红河州4个三七种植县的重金属污染程度依次表现为建水县>泸西>蒙自>个旧。(3)三七叶片和块根中都有比较严重的Cd、As、Pb超标,叶片中Cd、Pb、As超标率分别为64.7%、58.8%、94.1%,其中块根中Cd、As超标率分别高达82.4%和58.8%,而铜则均低于相关标准。(4)种植区三七具有较强的Cd富集能力和较弱的Cu、Pb富集能力,且三七叶片对Cu、Pb、As、Cd的富集系数总体均大于块根,三七对Cu、Pb、As、Cd有向地上部分转运的能力,三七中Cu、Pb、As、Cd转运系数平均值分别为1.61、4.15、3.05、1.22,转运能力依次Pb>As>Cu>Cd。

Yunnan is a high background area of heavy metal elements, but also the main producing area of Panax notoginseng. In recent years, the problem of heavy metal accumulation in Chinese herbal medicines hasattracted much attention. However, due to the reason of continuous cropping, Panax notoginseng cultivationhas extended from the traditional producing areas Wenshan to other areas. The accumulation of four heavymetal elements in soil and Panax notoginsengin four cities of Honghe Prefecture were studied in this paper.The results showed that：（1） the content of Cd in Panax notoginseng planting area was 0.113-1.01 mg/kg, Aswas 5.34-220.2 mg/kg, Cu was 30.6-143 mg/kg, and the average value was 0.48, 53.17 and 58.30 mg/kg,respectively, samples from many sampling points exceeded the standard;（2） studied by the comprehensivepollution index, it was found that the degree of heavy metal pollution in the four cities was in an order ofJianshui〉Luxi〉Mengzi〉Gejiu;（3） Cd, As and Pb in leaves and roots exceeded the standard seriously, andthe over standard rate of these three elements in leaves was 64.7%, 58.8% and 94.1%, respectively; the overstandard rate of Cd and As in roots reached 82.4% and 58.8%, while Cu was lower than the standard;（4）Panax notoginseng in planting area had higher enrichment ability of Cd, and that of Cu and Pb was lower, and the enrichment ability of Cu, Pb, As and Cd in leaves was higher than that of roots, Panax notoginseng had thetransfer ability of Cu, Pb, As and Cd to the aboveground parts, and the transfer coefficient was 1.61, 4.15, 3.05 and 1.22, respectively, and the transfer capacity followed the order of Pb〉As〉Cu〉Cd.