Lanctôt Chantal M, Cresswell Tom, Melvin Steven D
Australian Rivers Institute, School of Environment, Griffith University, Southport QLD 4215, Australia.
Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, NSW 2232, Australia.
Ecotoxicol Environ Saf. 2017 Oct;144:291-299. doi: 10.1016/j.ecoenv.2017.06.047. Epub 2017 Jun 20.
Metals and metalloids released through anthropogenic activities can accumulate in aquatic organisms, resulting in adverse effects in sensitive species. We investigated the influence of feeding regime and exposure complexity (i.e., mixture) on bioaccumulation kinetics and body distribution of common metal(loid) pollutants in Limnodynastes peronii during early post-embryonic development. Tadpoles were exposed to radiolabelled Cd, Se and Zn alone and in a mixture for 4 days, followed by 3 days depuration in clean water. One group was fed directly in exposure aquaria, whereas a second group was transferred to clean water for feeding, to investigate the potential influence of sorption to food on uptake. Bioconcentration factor and retention was observed to be greatest for Se. Results demonstrate that tadpoles accumulated and retained half the amount of Cd when exposed in mixture, suggesting that Se and/or Zn may have antagonistic effects against Cd uptake. Additionally, tadpoles fed directly in exposure water accumulated 2-3-times more Cd and Zn compared to tadpoles fed in clean water, indicating that the presence of food particles is an important factor that may influence uptake. Interestingly, this had a negligible impact on Se uptake. The study reveals how exposure conditions can influence the bioaccumulation of metal(loid)s, highlighting experimental factors as important considerations for both controlled toxicity experiments and for understanding exposure risks for amphibian populations.
通过人为活动释放的金属和类金属会在水生生物体内蓄积，对敏感物种产生不利影响。我们研究了摄食方式和暴露复杂性（即混合物）对后胚胎发育早期的佩氏沼蟾体内常见金属（类金属）污染物生物累积动力学和身体分布的影响。将蝌蚪单独暴露于放射性标记的镉、硒和锌以及它们的混合物中4天，然后在清洁水中进行3天的净化。一组直接在暴露水族箱中喂食，而另一组转移到清洁水中喂食，以研究食物吸附对摄取的潜在影响。观察到硒的生物浓缩系数和保留率最高。结果表明，蝌蚪在混合物中暴露时积累和保留的镉量减少了一半，这表明硒和/或锌可能对镉的摄取具有拮抗作用。此外，与在清洁水中喂食的蝌蚪相比，直接在暴露水中喂食的蝌蚪积累的镉和锌多2至3倍，这表明食物颗粒的存在是可能影响摄取的一个重要因素。有趣的是，这对硒的摄取影响可忽略不计。该研究揭示了暴露条件如何影响金属（类金属）的生物累积，强调了实验因素对于受控毒性实验和理解两栖动物种群暴露风险的重要性。
