George Mason University, Department of Environmental Science and Policy, USA; University of South Alabama, Department of Biology, USA.
University of South Alabama, Department of Biology, USA.
Chemosphere. 2019 Nov;235:952-958. doi: 10.1016/j.chemosphere.2019.06.166. Epub 2019 Jun 28.
Ecological risk of chemicals to aquatic-phase amphibians has historically been evaluated by comparing estimated environmental concentrations in surface water to surrogate toxicity data from fish species. Despite their obvious similarities, there are biological disparities among fish and amphibians that could affect their exposure and response to chemicals. Given the alarming decline in amphibians, in which anthropogenic pollutants play at least some role, investigating the risk of chemicals to amphibians is becoming increasingly important. Here, we evaluate relative sensitivity of fish and larval aquatic-phase amphibians to 45 different pesticides using existing data from three standardized toxicity test designs: (1) amphibian metamorphosis assay (AMA) with the African clawed frog (Xenopus laevis); (2) fish short-term reproduction assay (FSTRA) with the fathead minnow (Pimephales promelas); (3) fish early life stage test (ELS) with fathead minnows or rainbow trout (Oncorhynchus mykiss). The advantage of this dataset over previous work is that the underlying studies are consistent in exposure method, study duration, test species, endpoints measured, and number of concentrations tested. We found very strong positive relationships between fish and frog lowest adverse effect concentrations (LOAEC) for survival [Spearman's rank correlation (r) = 0.88], body weight (r = 0.86), and length (r = 0.89) with only one out of 45 chemicals (propiconazole) exhibiting 100-folder greater sensitivity in frogs relative to fish. While our results suggest comparable toxicity for pesticides between fish and aquatic-phase amphibians under these test conditions, further research with a greater diversity of amphibians and exposure scenarios will help determine the relevance of these results across species and life stages.
历史上，通过比较地表水中的估计环境浓度与鱼类物种的替代毒性数据，评估了化学物质对水生阶段两栖动物的生态风险。尽管鱼类和两栖动物有明显的相似之处，但它们之间存在生物学差异，这可能会影响它们对化学物质的暴露和反应。鉴于两栖动物数量的惊人下降，人为污染物至少在其中起到了一定的作用，因此调查化学物质对两栖动物的风险变得越来越重要。在这里，我们使用三种标准化毒性测试设计的现有数据来评估鱼类和幼体水生阶段两栖动物对 45 种不同农药的相对敏感性：（1）使用非洲爪蟾（Xenopus laevis）的两栖动物变态测定法（AMA）；（2）使用胖头鱼（Pimephales promelas）的鱼类短期繁殖测定法（FSTRA）；（3）使用胖头鱼或虹鳟（Oncorhynchus mykiss）的鱼类早期生活阶段测试（ELS）。与之前的工作相比，该数据集的优势在于，基础研究在暴露方法、研究持续时间、测试物种、测量的终点和测试的浓度数量方面都是一致的。我们发现鱼类和青蛙的最低不良效应浓度（LOAEC）之间存在非常强的正相关关系，包括生存（Spearman 秩相关（r）= 0.88）、体重（r = 0.86）和长度（r = 0.89），只有 45 种化学物质中的 1 种（丙环唑）在青蛙中的敏感性比鱼类高 100 倍。虽然我们的结果表明在这些测试条件下，鱼类和水生阶段两栖动物的农药毒性相当，但需要进一步用更多种类的两栖动物和暴露场景进行研究，以确定这些结果在物种和生命阶段的相关性。
