Uptake route and resulting toxicity of silver nanoparticles in Eisenia fetida earthworm exposed through Standard OECD Tests.
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.
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.
Nerea
N
Garcia-Velasco
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.
Maite
M
Gandariasbeitia
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.
Amaia
A
Irizar
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. manu.soto@ehu.es.
Manuel
M
Soto
D000818:Animals; D053768:Metal Nanoparticles / Q000633:toxicity*; D009835:Oligochaeta / Q000502:physiology*; D066150:Organisation for Economic Co-Operation and Development; D012834:Silver / Q000378:metabolism* / Q000633:toxicity; D012987:Soil; D012989:Soil Pollutants / Q000378:metabolism* / Q000633:toxicity; D018675:Toxicity Tests / Q000379:methods* / Q000592:standards
D012987:Soil; D012989:Soil Pollutants; D012834:Silver
Ag NPs; E. fetida; OECD standard toxicity tests; Soil; Uptake routes