Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China.
Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China.
Sci Total Environ. 2020 Jul 15;726:138550. doi: 10.1016/j.scitotenv.2020.138550. Epub 2020 Apr 7.
The bioaccumulation and trophic transfer of As along food webs in freshwater ecosystems remain largely unknown. In this study, multiple environmental and biological samples were collected from a closed realgar mining area in South China. The As concentrations in the surface water, sediments and soils in the mining area were 0.62-3293 μg/L, 9.53-4543 mg/kg and 7.32-5008 mg/kg, respectively, and gradually decreased with distance from the central mining sites, indicating that historic As mining activities had an eminent impact on As contamination around the mine. The As concentrations in aquatic organisms ranged from 0.60 mg/kg to 45.75 mg/kg and varied markedly among sites and species, reflecting the influence of various physiologic and environmental factors. Arsenic species identified by liquid chromatography inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) were mainly organic, comprising 8% to 66% of the total As. Both the proportions and concentrations of inorganic As were positively correlated with total As. This correlation could be attributed to the higher assimilation and accumulation of inorganic As or the lower biotransformation ability of inorganic As with the increasing total As in the studied organisms. Values of δC and δN in aquatic organisms ranged from -30.59‰ to -15.07‰ and from 4.31‰ to 12.98‰, respectively, indicating multiple trophic levels and variety in the diet sources of these organisms. The δN increased distinctly in the order of planktivorous<herbivorous<omnivorous<carnivorous, which is generally consistent with the increasing trophic levels in the freshwater ecosystem. No significant correlation was observed between As concentrations and δN in the freshwater organisms, suggesting no biomagnification of As in the food web.
在淡水生态系统中，生物积累和食物链中砷的转移仍然很大程度上未知。在这项研究中，从中国南方一个封闭的雄黄矿区采集了多个环境和生物样本。矿区地表水、沉积物和土壤中的砷浓度分别为 0.62-3293μg/L、9.53-4543mg/kg 和 7.32-5008mg/kg，并随距中心矿区距离的增加而逐渐降低，表明历史上的砷矿开采活动对矿区周围的砷污染有显著影响。水生生物体内的砷浓度范围为 0.60mg/kg 至 45.75mg/kg，不同地点和物种之间差异显著，反映了各种生理和环境因素的影响。通过液相色谱电感耦合等离子体质谱法（HPLC-ICP-MS）鉴定的砷形态主要为有机形态，占总砷的 8%-66%。无机砷的比例和浓度均与总砷呈正相关。这种相关性可能归因于研究生物体内无机砷的较高同化和积累，或随着总砷的增加，无机砷的生物转化能力降低。水生生物的 δC 和 δN 值分别在-30.59‰至-15.07‰和 4.31‰至 12.98‰之间，表明这些生物具有多个营养级和多种食物来源。δN 值按滤食性<草食性<杂食性<肉食性的顺序明显增加，这与淡水生态系统中营养级别的增加基本一致。水生生物中砷浓度与 δN 值之间未观察到显著相关性，表明砷在食物网中没有生物放大。
