Liu Wen-hua, Zhao Jing-zhu, Ouyang Zhi-yun, Söderlund Leif, Liu Guo-hua
Research Center for Eco-Environment Sciences, Chinese Academy of Sciences, Beijing, China.
Environ Int. 2005 Aug;31(6):805-12. doi: 10.1016/j.envint.2005.05.042.
A potential hazard to Beijing was revealed due to the accumulation trend of heavy metals in agricultural soils with sewage irrigation, which results in metal contamination and human exposure risk. Samples including soils and plants were collected to assess the impacts of sewage irrigation on the irrigated farming area of Beijing. Concentrations of the five elements Cd, Cr, Cu, Zn, and Pb were determined in samples to calculate the accumulation factor and to establish a basis for environmental protection and the suitability of sewage irrigation for particular land use in the urban-rural interaction area of Beijing. Using reference values provided by the Beijing Background Research Cooperative Group in the 1970s, the pollution load index (PLI), enrichment factor (EF), and contamination factor (CF) of these metals were calculated. The pollution load indices (sewage irrigation land 3.49) of soils indicated that metal contamination occurred in these sites. The metal enrichment (EF of Cd 1.8, Cr 1.7, Cu 2.3, Zn 2.0, Pb 1.9) and the metal contamination (CF of Cd 2.6, Cr 1.5, Cu 2.0, Zn 1.7, Pb 1.6) showed that the accumulation trend of the five toxic metals increased during the sewage irrigation as compared with the lower reference values than other region in China and world average, and that pollution with Cd, Cu, Zn, and Pb was exacerbated in soils. The distributions of these metals were homogeneous in the irrigation area, but small-scale heterogeneous spatial distribution was observed. Irrigation sources were found to affect heavy metal distributions in soils. It was suggested that heavy metal transfer from soils to plants was a key pathway to human health exposure to metal contamination. However, with the expansion of urban areas in Beijing, soil inhalation and ingestion may become important pathways of human exposure to metal contamination.
由于污水灌溉导致北京农业土壤中重金属的积累趋势，揭示了对北京的潜在危害，这会导致金属污染和人类暴露风险。采集了包括土壤和植物在内的样本，以评估污水灌溉对北京灌溉农田地区的影响。测定了样本中镉、铬、铜、锌和铅这五种元素的浓度，以计算积累因子，并为北京城乡互动地区的环境保护和特定土地利用的污水灌溉适宜性奠定基础。利用20世纪70年代北京背景研究合作组提供的参考值，计算了这些金属的污染负荷指数（PLI）、富集因子（EF）和污染因子（CF）。土壤的污染负荷指数（污水灌溉土地为3.49）表明这些地点发生了金属污染。金属富集（镉的EF为1.8、铬为1.7、铜为2.3、锌为2.0、铅为1.9）和金属污染（镉的CF为2.6、铬为1.5、铜为2.0、锌为1.7、铅为1.6）表明，与中国其他地区和世界平均水平的较低参考值相比，污水灌溉期间这五种有毒金属的积累趋势增加，并且土壤中镉、铜、锌和铅的污染加剧。这些金属在灌溉区域的分布是均匀的，但观察到小规模的非均匀空间分布。发现灌溉水源会影响土壤中重金属的分布。有人提出，重金属从土壤向植物的转移是人类健康暴露于金属污染的关键途径。然而，随着北京城市面积的扩大，土壤吸入和摄入可能成为人类暴露于金属污染的重要途径。
