Toxicokinetics of Ag in the terrestrial isopod Porcellionides pruinosus exposed to Ag NPs and AgNO3 via soil and food

Abstract

Soares, Amadeu M.V.M.; Loureiro, Susana. 2016. Toxicokinetics of Ag in the terrestrial isopod Porcellionides pruinosus exposed to Ag NPs and AgNO3 via soil and food. Ecotoxicology, 25 (2). 267-278. 10.1007/s10646-015-1585-7 Contact CEH NORA team at noraceh@ceh.ac.ukThe NERC and CEH trademarks and logos ('the Trademarks') are registered trademarks of NERC in the UK and other countries, and may not be used without the prior written consent of the Trademark owner. Isopods were exposed to contaminated Lufa 2.2 soil or alder leaves as food.Uptake and elimination rate constants for soil exposure did not significantly differ between Ag NPs and ionic Ag at 30 and 60 mg Ag/kg. For dietary exposure, the uptake rate constant was up to 5 times higher for Ag NPs than for AgNO3, but this was related to feeding activity and exposure concentrations, while no difference in the elimination rate constants was found. When comparing both routes, dietary exposure resulted in lower Ag uptake rate constants but elimination rate constants did not differ. A fast Ag uptake was observed from both routes and most of the Ag taken up seemed not to be eliminated. Synchrotron X-ray fluorescence showed Ag in the S-cells of the hepatopancreas, thus supporting the observations from the kinetic experiment (i.e. low elimination). In addition, our results show that isopods have an extremely high Ag accumulation capacity, suggesting the presence of an efficient Ag storage compartment.

Toxicity-based toxicokinetic/toxicodynamic assessment of bioaccumulation and nanotoxicity of zerovalent iron nanoparticles in <em>Caenorhabditis elegans</em>

“…We found that Fe 0 NP body burdens and BCFs were relatively low in worms, similar to results of other studies and BCFs of Fe 0 NPs in medaka fish. 10,59 The BMFs were smaller than 1 in both waterborne and food-borne Fe 0 NP-exposed worms ( Table 2), indicating that biomagnification effects did not occur in the food-chain structure of E. coli-C. elegans. The biomagnification effects of various metal-based NPs, such as CdSe quantum dots, Au, CeO 2 , and TiO 2 , have been evidenced in several studies.…”

“…58 The trends of TBTK estimates were also consistent with a previous study where values of uptake parameters were higher than elimination ones ( Table 2). 59 The uptake constants of waterborne Fe 0 NP-exposed worms were higher than those of food-borne-treated ones, suggesting that Fe 0 NPs accumulated easily in worms via waterborne routes ( Table 2). We found that Fe 0 NP body burdens and BCFs were relatively low in worms, similar to results of other studies and BCFs of Fe 0 NPs in medaka fish.…”

Effect of Concentration of Silver Nanoparticles on the Uptake of Silver from Silver Nanoparticles in Soil

“…Studies to understand the uptake, kinetics and transformatoin of metal nanoparticles in terrestrial ecosystems usually include the terrestrial isopods [29][30][31]. Terrestrial ispods enable the study of uptake and transformation of metal nanoparticles because of their ability to uptake nanopartiles extensively through the oral route.…”

An in vitro – in vivo integrated approach for hazard and risk assessment of silver nanoparticles for soil organisms

“…Earthworms have macrophage immune cells called coelomocytes, and their viability has previously been shown to be affected by exposure to AgNPs [31]. End-points of toxicity that were assessed in the current thesis include cell viability, intracellular ROS production, reduction in ATP cellular levels, alterations in the integrity of the mitochondrial permeability transition pore opening, and induction of TNF-α [94][95][96][97][98][99]. At the individual level, in vivo responses to AgNP exposures may confirm mechanistic insights derived from in vitro studies, and toxicity end-points commonly studied are survival, growth rate and reproduction (cocoon production).…”

“…Thus, neither particulate nor ionic forms of Ag seemed to be associated with MTs. It is possible that Ag ions are sequestered in the insoluble granules, as was suggested for isopods in which an inert fraction of internalised Ag was assumed after exposure to AgNPs [95] The presumed role of MTs in AgNP toxicity to earthworms is generally based on indirect observations, quantifying this protein in tissues after exposure or looking at gene expression profiles. An interesting approach is by tissue fractionation [90,96], as was done in the current thesis (Chapter 5).…”