Li Junhui, Lu Ying, Shim Hojae, Deng Xianglian, Lian Jin, Jia Zhenglei, Li Jianhua
College of Natural Resources and Environment, South China Agricultural University, Guangzhou, 510642, China.
J Environ Monit. 2010 Feb;12(2):466-71. doi: 10.1039/b916389a. Epub 2009 Oct 29.
To investigate the mobility and availability of metals from soil to plant, concentrations of zinc (Zn), copper (Cu), lead (Pb), cadmium (Cd), mercury (Hg) and arsenic (As) in topsoils and plants (lettuce, scallion, celery, tomato, carambola, wampee and longan) collected from the area around a petrochemical complex in Guangzhou, China, were analyzed. The modified European Community Bureau of Reference (BCR) three-step sequential extraction procedure was applied to determine the concentration of metal fractions in soils. The results showed that the distribution of Zn, Cu, Pb and Cd in four fractions varied greatly among the soil samples, and 18.8% of vegetable and fruit samples for Cd and 5.8% for Pb exceeded the maximum permissible levels in food of China. Soil-to-plant transfer coefficients were in the order of Cd>Zn>Cu>Hg>As>Pb, suggesting Cd being the most mobile and available to plants among the metals studied. Principal component analysis indicated that metal fractions and soil physicochemical properties (pH, organic matter, cation exchange capacity, clay content and electrical conductivity) affected metal uptake by plants. Furthermore, atmospheric deposition may be another important factor for the accumulation of metals in plants.
为研究土壤中金属向植物的迁移性和有效性，对采自中国广州某石化厂区周边的表层土壤以及植物（生菜、葱、芹菜、番茄、杨桃、黄皮和龙眼）中锌（Zn）、铜（Cu）、铅（Pb）、镉（Cd）、汞（Hg）和砷（As）的含量进行了分析。采用改进的欧洲共同体标准物质局（BCR）三步连续提取法测定土壤中金属形态的含量。结果表明，土壤样品中锌、铜、铅和镉在四种形态中的分布差异很大，18.8%的蔬菜和水果样品镉含量以及5.8%的铅含量超过了中国食品中的最大允许限量。土壤到植物的转移系数顺序为Cd>Zn>Cu>Hg>As>Pb，表明在所研究的金属中镉对植物的迁移性和有效性最高。主成分分析表明，金属形态和土壤理化性质（pH值、有机质、阳离子交换容量、粘土含量和电导率）影响植物对金属的吸收。此外，大气沉降可能是植物中金属积累的另一个重要因素。
