State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, PR China.
Sci Total Environ. 2018 Feb 1;613-614:1324-1330. doi: 10.1016/j.scitotenv.2017.09.180. Epub 2017 Oct 5.
The distribution of metals in cyanobloom-forming lakes, and potential risks of these metals during irrigation with water derived from the bloom were evaluated in this study. Seven metals were monitored throughout a cyanobacterial bloom season in Lake Taihu. Cyanobloom bio-dilution of the targeted metals could be explained by the negative relationships between total phytoplankton metal contents (Cu, Fe, Zn, Pb and Cr) and Chl a concentrations (p<0.05). Meanwhile, the ratios of extracellular bound to total cellular bound metals (Cu, Zn, Pb, Cr and Cd) were positively correlated with the ratios of cyanophyta to total phytoplankton (p<0.01), indicating the enhanced extracellular bound of these metals during cyanobloom period. Secondly, Cd, Pb and Cr were detected in several local vegetables. In comparison to reference vegetables, vegetables (e.g., radish, soybean, and cowpea), which were irrigated with cyanobloom broth collected from Lake Taihu, presented high health risk index (HRI) and were not safe for human consumption. Collectively, the frequent dominant colonial Microcystis blooms which performed high metal affinity might mediate the distribution of heavy metals in lake and potentially transferred these pollutants into terrestrial system.
本研究评估了蓝藻水华形成湖中金属的分布，以及用蓝藻水华产生的水进行灌溉时这些金属的潜在风险。在太湖蓝藻水华季节，监测了七种金属。蓝藻生物稀释作用可以解释总浮游植物金属含量（Cu、Fe、Zn、Pb 和 Cr）与 Chl a 浓度之间的负相关关系（p<0.05）。同时，细胞外结合金属与总细胞结合金属的比例（Cu、Zn、Pb、Cr 和 Cd）与蓝藻与总浮游植物的比例呈正相关（p<0.01），表明在蓝藻水华期间这些金属的细胞外结合增强。其次，在一些当地蔬菜中检测到 Cd、Pb 和 Cr。与对照蔬菜相比，用取自太湖的蓝藻菌液灌溉的蔬菜（如萝卜、大豆和豇豆）的健康风险指数（HRI）较高，不适合人类食用。总体而言，频繁出现的具有高金属亲和力的优势团状微囊藻水华可能会调节湖泊中重金属的分布，并可能将这些污染物转移到陆地系统中。
