Department of Plant and Soil Sciences, University of Kentucky, Lexington, Kentucky 40546, United States.
Environ Sci Technol. 2012 Sep 4;46(17):9753-60. doi: 10.1021/es3025325. Epub 2012 Aug 24.
To determine if nanoparticles (NPs) could be transferred from soil media to invertebrates and then to secondary consumers, we examined the trophic transfer of Au NPs along a simulated terrestrial food chain. Earthworms (Eisenia fetida) were exposed to Au NPs in artificial soil media and fed to juvenile bullfrogs (Rana catesbeina). Earthworm Au concentrations were continuously monitored so that the cumulative dose to bullfrogs could be accurately estimated throughout the experiment. We exposed a second group of bullfrogs to equivalent doses of Au NPs by oral gavage to compare the bioavailability of NPs through direct exposure to trophic exposure. We observed accumulation of Au in liver, kidney, spleen, muscle, stomach, and intestine in both treatment groups. Tissue concentrations decreased on average of approximately 100-fold with each trophic-step. The total assimilated dose averaged only 0.09% of the administered dose for direct exposure (oral gavage), but 0.12% for the trophic exposure. The results suggest that manufactured NPs present in soil may be taken up into food chains and transferred to higher order consumers. They also suggest that Au NPs may be more bioavailable through trophic exposure than direct exposure and that trophic transfer may influence the biodistribution of particles once absorbed.
为了确定纳米颗粒（NPs）是否可以从土壤介质转移到无脊椎动物，然后再转移到次级消费者，我们沿着模拟的陆地食物链研究了 Au NPs 的营养转移。将 Au NPs 暴露于人工土壤介质中的蚯蚓（Eisenia fetida）并喂给幼蛙（Rana catesbeina）。连续监测蚯蚓的 Au 浓度，以便在整个实验过程中准确估计对蛙的累积剂量。我们通过口服灌胃使第二组蛙暴露于等效剂量的 Au NPs，以比较通过直接暴露于营养暴露的 NPs 的生物利用度。我们观察到两组处理均在肝脏，肾脏，脾脏，肌肉，胃和肠中积累了 Au。组织浓度平均下降了约 100 倍，与每个营养阶段相比。直接暴露（口服灌胃）的总吸收剂量平均仅为给药剂量的 0.09％，而营养暴露的总吸收剂量为 0.12％。结果表明，土壤中存在的人造 NPs 可能被吸收到食物链中并转移到更高的消费者。它们还表明，与直接暴露相比，通过营养暴露 Au NPs 的生物利用度可能更高，并且一旦被吸收，营养转移可能会影响颗粒的生物分布。
