School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China; Key Laboratory of Water Quality Safety and Protection in Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou 510006, China; Department of Biology and Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.
Department of Biology and Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.
Ecotoxicol Environ Saf. 2014 Jun;104:143-51. doi: 10.1016/j.ecoenv.2014.02.017. Epub 2014 Mar 25.
Owing to the Industrial Revolution in the late 1970s, heavy metal pollution has been regarded as a serious threat to mangrove ecosystems in the region of the Pearl River Estuary, potentially affecting human health. The present study attempted to characterize the ecological risk of heavy metals (Cd, Cr, Cu, Mn, Ni, Pb and Zn) in Nansha mangrove, South China, by estimating their concentrations in the surface sediment. In addition, the pollution history of heavy metals was examined by determining the concentrations of heavy metals along the depth gradient. The phytoremediation potential of heavy metals by the dominant plants in Nansha mangrove, namely Sonneratia apetala and Cyperus malaccensis, was also studied. Results found that the surface sediment was severely contaminated with heavy metals, probably due to the discharge of industrial sewage into the Pearl River Estuary. Spatial variation of heavy metals was generally unobvious. The ecological risk of heavy metals was very high, largely due to Cd contamination. All heavy metals, except Mn, decreased with depth, indicating that heavy metal pollution has been deteriorating since 1979. Worse still, the dominant plants in Nansha mangrove had limited capability to remove the heavy metals from sediment. Therefore, we propose that immediate actions, such as regulation of discharge standards of industrial sewage, should be taken by the authorities concerned to mitigate the ecological risk posed by heavy metals.
由于 20 世纪 70 年代末的工业革命，重金属污染已被视为珠江口地区红树林生态系统的严重威胁，可能会影响人类健康。本研究试图通过估计表层沉积物中重金属（Cd、Cr、Cu、Mn、Ni、Pb 和 Zn）的浓度来描述南沙红树林的重金属生态风险。此外，通过测定重金属在深度梯度上的浓度，研究了重金属的污染历史。还研究了南沙红树林主要植物海桑和香蒲对重金属的植物修复潜力。结果发现，表层沉积物受到重金属的严重污染，这可能是由于工业污水排入珠江口所致。重金属的空间变化通常不明显。重金属的生态风险非常高，主要是由于 Cd 污染造成的。除 Mn 外，所有重金属随深度的增加而降低，表明自 1979 年以来，重金属污染一直在恶化。更糟糕的是，南沙红树林的主要植物去除沉积物中重金属的能力有限。因此，我们建议有关部门立即采取行动，如规范工业污水排放标准，以减轻重金属带来的生态风险。
