水环境中藻毒素生态风险的物种敏感性分布评价

藻毒素对人体的健康风险已受普遍关注,然而其对水生态物种敏感性分布的影响尚不明朗。本研究采集已有实验数据,利用种间相关性分析(ICE)模型和物种敏感性分布评估(SSDs)方法,筛选了64个水生生物物种的71组急性毒性数据(EC50),构建水生生物对肝毒素(节球藻毒素、柱孢藻毒素)和神经毒素(类毒素、贝毒素)的SSD方程。在此基础上,计算不同暴露浓度下的潜在影响比例(PAF)以及保护95%物种基础上藻毒素对水生生物的生态风险阈值(HC5),比较不同类别生物对藻毒素的敏感性以及藻毒素对水生生物的生态风险。结果表明:(1)在95%物种保护保证率下,节球藻毒素、柱孢藻毒素、类毒素和贝毒素对全部物种的HC5值分别为74.96、205.39、194.39、0.3μg·L~(-1),贝毒素水生态风险最高,柱孢藻毒素最低。(2)柱孢藻毒素、类毒素对无脊椎动物的HC5值分别为122.93、95.19μg·L~(-1),低于全部物种的HC5值,无脊椎动物受柱孢藻毒素、类毒素影响较其他物种大。(3)物种潜在影响比例可明确表征敏感性,柱孢藻毒素、类毒素在各浓度暴露情景下对无脊椎动物的PAF值均高于脊椎动物,显示无脊椎动物的敏感性较高。

Assessing Ecological Risk of Cyanotoxins Based on Interspecies Correlation Estimation and Species Sensitivity Distributions

The risk of cyanotoxins to human health has been widely concerned. However, their effect on aquatic species sensitivity distribution was not well understood. This study aimed to assess the ecological risks of two typi￣cal cyanobacterial hepatotoxins (nodularins, cylindrospermopsin) and two typical cyanobacterial neurotoxins (ana￣toxin￣a, saxitoxins) by employing the interspecies correlation estimation (ICE) and species sensitivity distributions (SSDs) models. SSDs were constructed based on 71 available sets of acute toxicity data covering 64 aquatic organ￣isms exposure to cyanotoxins. The potentially affected fractions (PAF) under various concentrations and the hazard￣ous concentrations for 5% of the species (HC5 ) were calculated and compared among different aquatic species. Re￣sults show that the estimated HC5 values for nodularins, cylindrospermopsin, anatoxin￣a and saxitoxins were 74.96μg?L￣1, 205.39μg?L￣1, 194.39μg?L￣1and 0.3μg?L￣1, respectively, suggesting that the hazardous risk of species is assessed at higher and lower level for saxitoxins and cylindrospermopsin. The invertebrates exposure to cylindrosper￣mopsin and anatoxin￣a presented lower HC5 than that of the all aquatic organisms with 122.93μg?L￣1 and 95.19μg?L￣1 , respectively, which indicate that cylindrospermopsin and anatoxin￣a cause more damage to invertebrates than other species. The PAF of 10￣1000μg?L￣1 cylindrospermopsin and anatoxin￣a to invertebrates were higher than that of vertebrates, suggesting that invertebrates are more sensitive to cylindrospermopsin and anatoxin￣a than vertebrates.