School of Environment, Science and Engineering, Southern Cross University, Military Road, East Lismore, New South Wales, 2480, Australia.
Environ Sci Pollut Res Int. 2018 Aug;25(24):24281-24292. doi: 10.1007/s11356-018-2441-0. Epub 2018 Jun 14.
Phytocapping is increasingly regarded as an economical and environmentally sustainable post-closure landfill management strategy. During 2013, a phytocap comprised of koala habitat trees was established on a historic landfill site in Lismore as part of an Australian trial program (A-ACAP). This case study was conducted to determine trace element contamination of the Lismore phytocap soil and foliage, and identify risks to grazing koalas. Foliage of Eucalyptus tereticornis, a key koala food tree, and Acacia melanoxylon, a reference native species, were assessed at the phytocap and an uncontaminated reference site. Concentrations of Ag, As, Hg and Pb were significantly higher in foliage from the phytocap compared to that from the reference site (p < 0.0001). Mean trace element concentrations in phytocap E. tereticornis foliage were compliant with state and international standards for contaminants in food and animal feed (NSW State Government, 2010; WHO and FAO, 2015) and soil was compliant with national health-based investigation levels for contaminated sites (NEPC, 2011). However, contaminant distribution was not homogenous, and As and Pb concentrations exceeded guidelines in some soil and foliage samples. Based on available guidelines and weekly dietary intake calculations, risks to koala health posed by trace element contamination of phytocap foliage are currently low, though should be managed by continued monitoring as the vegetation matures.
植物覆盖层越来越被认为是一种经济且环境可持续的封场后垃圾填埋场管理策略。2013 年，作为澳大利亚试验计划（A-ACAP）的一部分，在利斯莫尔的一个历史垃圾填埋场建立了一个由考拉栖息地树木组成的植物覆盖层。本案例研究旨在确定利斯莫尔植物覆盖层土壤和枝叶中的微量元素污染情况，并确定对放牧考拉的风险。评估了关键的考拉食物树桉树 tereticornis 和参考本地物种金合欢 melanoxylon 的枝叶。与参考地点相比，来自植物覆盖层的桉树 tereticornis 和金合欢 melanoxylon 枝叶中的 Ag、As、Hg 和 Pb 浓度明显更高（p<0.0001）。植物覆盖层中桉树 tereticornis 枝叶中的微量元素浓度符合国家和国际标准中食品和动物饲料中的污染物标准（新南威尔士州政府，2010 年；世界卫生组织和粮农组织，2015 年），土壤符合国家基于健康的污染场地调查水平（NEPC，2011 年）。然而，污染物分布不均匀，一些土壤和枝叶样本中的 As 和 Pb 浓度超过了指南值。根据现有的指南和每周膳食摄入量计算，植物覆盖层枝叶中微量元素污染对考拉健康构成的风险目前较低，但随着植被的成熟，应通过持续监测进行管理。
