乐昌Pb/Zn矿区水稻土中Pb的形态分布特征

对多年利用矿山废水灌溉的水稻土中Pb的化学形态、植物有效态和动物／人有效态进行了分析研究。结果表明，土壤中Pb的碳酸盐结合态、可交换态、有机结合态和Fe-Mn氧化物结合态含量分别是363、338、185和155mg／kg，其总和占总Pb含量的72．70％，表明其较高的环境敏感性；动物／人有效态Pb含量为1085mg／kg。土壤有机态Pb与植物中Pb含量相关性最高，表明用有机态表征土壤Pb的植物有效态比惯常使用的DTPA态要好。植物有效态与动物／人有效态含量相比，前者为后者的17．05％，表明土壤Pb污染对当地动物／人的潜在生态危害远远大于水稻等农作物；Fe-Mn氧化物结合态Pb与植物有效态（即有机结合态）及动物／人有效态Pb相关性最好，表明该形态对土壤Pb的生物有效性具有积极作用。

Existence State of Lead in Paddy Soils Contaminated in Lead-Zinc Mine of Lechang,China

The state of Pb existing in rice plant and corresponding soils from paddy fields irrigated with untreated mining wastewater lead/zinc mine for many years, as well as existing in plants, animal and human bodies were analyzed. Results showed that the Pb content in carbonate, convertible substances, organic substances and substances combined with Fe-Mn oxide are 363, 338, 185 and 155 mg/kg, respectively. Sum Pb of the four forms accounted for 72.70 % of total soil Pb content indicating its high environmental sensibility. The available Pb content in animal/human bodies was 1085 mg/kg. The highest correlation was between the organic Pb in soil and in plants, which means the organic Pb content in plants was better than DTPA as the indicator of soil Pb content. The organic Pb content in plants was 17.05% of that in animal/human bodies, showing the potential harmful effect of Pb pollution in soil to anlmal/human was much more serious than that to crops like rice. Fe-Mn oxide-bound Pb was correlated most significantly to that in plants, animal and human bodies, indicating that Pb existing in this state played an active role for bioavailability of Pb in soil.