University of Aveiro, Department of Biology & CESAM, 3810-193 Aveiro, Portugal.
Aarhus University, Department of Bioscience, Vejlsøvej 25, 8600 Silkeborg, Denmark.
Sci Total Environ. 2018 Aug 1;631-632:326-333. doi: 10.1016/j.scitotenv.2018.02.332. Epub 2018 Mar 16.
Effects of pollutants are mostly assessed using standard testing procedures, which cover a fraction of the animals' life cycle. Although, in nature species are exposed during multiple generations of sub-lethal doses of persistent chemicals. In the present study, we focused on the multigenerational (MG) effects of silver in Folsomia candida during 6 generations using the EC50 for reproduction as exposure concentration. We tested 9 different exposure scenarios, going from continuous 6 generations Ag exposure over pulse exposure (i.e. one generation clean, next contaminated, next clean etc.) to gradually increasing the number of exposure generations, with a final transfer to clean media. The biological endpoints assessed included survival, reproduction and size, with reproduction being the most sensitive. The biological response depended on the specific MG scenario, e.g. the 6 Ag MG caused a decreased number of juveniles from F4, whereas the pulse exposure experienced an increase in reproductive output when in clean soil. It is uncertain whether Ag causes transgenerational effects, but the reproduction levels in both pulse exposures are lower than in continuous control over the 6 generations which could be due to transference of Ag by the maternal generation. Overall, population size distribution seemed to indicate a delay in time for egg laying, with close relationship between adult survival, organisms size and reproduction output. Size monitoring allowed significant added interpretation possibilities and we strongly recommend the addition of this endpoint to the standard guideline. The smaller observed size range can have implications in terms of adaptation potential, carrying associated increased risk.
污染物的影响主要通过标准测试程序进行评估，这些程序仅涵盖动物生命周期的一部分。然而，在自然界中，物种在亚致死剂量的持久性化学物质的多代暴露下受到影响。在本研究中，我们使用繁殖的 EC50 作为暴露浓度，在 Folsomia candida 中研究了银的多代（MG）效应，共进行了 6 代。我们测试了 9 种不同的暴露情景，从连续 6 代的 Ag 暴露到脉冲暴露（即一代清洁，下代污染，下代清洁等），逐渐增加暴露代的数量，最后转移到清洁介质。评估的生物学终点包括存活率、繁殖和大小，其中繁殖是最敏感的。生物反应取决于特定的 MG 情景，例如，6 代 Ag MG 导致 F4 的幼体数量减少，而在清洁土壤中脉冲暴露时繁殖产量增加。目前还不确定 Ag 是否会引起跨代效应，但在连续对照的 6 代中，两种脉冲暴露的繁殖水平都低于对照，这可能是由于母体代将 Ag 转移所致。总体而言，种群大小分布似乎表明产卵时间延迟，成虫存活率、生物大小和繁殖产量之间存在密切关系。大小监测提供了更多的解释可能性，我们强烈建议在标准指南中增加这一终点。观察到的较小范围可能会对适应潜力产生影响，并带来相关的更高风险。
