Garcia-Velasco Nerea, Gandariasbeitia Maite, Irizar Amaia, Soto Manuel
Cell Biology in Environmental Toxicology (CBET) Research Group, Dept. Zoology and Animal Cell Biology, Faculty of Science and Technology and Research Centre for Experimental Marine Biology and Biotechnology PIE-UPV/EHU, University of the Basque Country UPV/EHU, E-48080, Bilbao, Basque Country, Spain.
Ecotoxicology. 2016 Oct;25(8):1543-1555. doi: 10.1007/s10646-016-1710-2. Epub 2016 Sep 10.
Despite the increasing interest in silver nanoparticles toxicity still few works dealt with the hazards of nanosized Ag in soils (either dissolved in pore water or coupled to colloids) although disposal of biosolids in landfills has been reported as the major source of silver nanoparticles in terrestrial environments. Presently, Eisenia fetida was used to assess the toxicity of 5 nm sized PVP-PEI coated silver nanoparticles in soil through the implementation of different exposure media Standard Toxicity Tests (Paper Contact and Artificial Soil -OECD-207- and Reproduction -OECD-222- Tests) together with cellular biomarkers measured in extruded coelomocytes. In order to decipher the mode of action of silver nanoparticles in soil and the uptake routes in earthworms, special attention was given to the Ag accumulation and distribution in tissues. High Ag accumulation rates, weight loss, and mortality due to the disruption of the tegument could be the result of a dermal absorption of Ag ions released from silver nanoparticles (Paper Contact Test). However, autometallography showed metals mainly localized in the digestive tract after Artificial Soil Test, suggesting that Ag uptake occurred mostly through soil ingestion. That is, silver nanoparticles attached to soil colloids seemed to be internalized in earthworms after ingestion of soil and transferred to the digestive gut epithelium where at high doses they have triggered severe effects at different levels of biological complexity.
尽管人们对银纳米颗粒的毒性越来越感兴趣，但仍很少有研究涉及土壤中纳米银（溶解在孔隙水中或与胶体结合）的危害，尽管据报道，垃圾填埋场中生物固体的处置是陆地环境中银纳米颗粒的主要来源。目前，通过实施不同的暴露介质标准毒性试验（滤纸接触试验和人工土壤试验——经合组织207号试验以及繁殖试验——经合组织222号试验），并结合在挤出的体腔细胞中测量的细胞生物标志物，利用赤子爱胜蚓评估了5纳米大小的聚乙烯吡咯烷酮-聚乙烯亚胺包覆银纳米颗粒在土壤中的毒性。为了解释银纳米颗粒在土壤中的作用方式以及蚯蚓的吸收途径，特别关注了银在组织中的积累和分布。由于银纳米颗粒释放的银离子经皮肤吸收，高银积累率、体重减轻以及由于体表破坏导致的死亡率可能是其结果（滤纸接触试验）。然而，自动金相分析表明，在人工土壤试验后，金属主要定位于消化道，这表明银的吸收主要通过土壤摄入发生。也就是说，附着在土壤胶体上的银纳米颗粒在蚯蚓摄入土壤后似乎被内化，并转移到消化肠道上皮，在高剂量下，它们在不同生物复杂程度水平上引发了严重影响。
