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We investigated how different carbonized materials, or chars (olive mill pomace biochar (BC) and urban greens pruning residues hydrochar (HC)) affect an important member of soil fauna, the terrestrial isopod Porcellio scaber. The selection behavior of isopods towards chars after a 48 h exposure was studied in (i) soil-char amended tests with single and multiple choices, and (ii) tests with chars offered as pure material. Finally, we exposed the isopods to char-amended soils for a period of 14 days to follow the effect on food consumption, body mass and activities of enzymes that are commonly altered upon stressor exposure (acetylcholinesterase, AChE, and glutathione S-transferase, GST). We showed that isopods are able to select between char amended and un-amended soil and different forms of char amendments: a clear preference for BC, and avoidance of HC were evidenced. The preferences remained the same when the chars were sterilized leading to the conclusion that initial microorganism composition was not the reason for selection, but selection was governed by other chars' physico-chemical properties. It remains to be elucidated which of these properties were the dominant reason for the selection. We also showed that isopods intentionally use BC as food at a similar rate to alder leaves. Medium-term exposure to HC resulted in adverse effects on isopods because it led to reduced feeding and growth, in addition to increasing GST activity, although no alterations in AChE activity were found. We suggest that behavioral tests with P. scaber could be used as a fast, reliable and economically feasible screening method for determining the safety of chars for the soil environment. Results represent significant contribution in the field of char toxicity testing, highlighting the importance of tests with isopods as important members of soil meso fauna, with the aim of influencing environmental policies and quality standards., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

We investigated the effects of a commercial pigment grade rutile TiO2 on the terrestrial isopod Porcellio scaber in three locations that differed in terms of abiotic and biotic conditions: the laboratory, open air, and the closed barn. Mortality and isopod energy reserves (digestive gland total proteins, lipids and carbohydrates) were not affected following 14days exposure to up to 1000mg TiO2 per kg dry leaves (mg/kg) under any experimental scenario. However, in the field tests, isopods consumption of TiO2-coated leaves was reduced compared to that of uncoated leaves and the decrease was not dose-dependent. The highest reduction was in the closed barn (45-56%) rather than in the open-air (38-40%). In laboratory-based food choice tests, isopods neither preferred nor avoided leaves coated with TiO2, suggesting that rather than sensing the TiO2 on the leaves directly, the isopods under open-air and barn exposure responded to altered attractiveness and/or palatability of the TiO2 amended leaves. We propose that this could be due to altered microbial population on the leaves, a hypothesis that requires further investigation. Although short-term exposure to atmospheric deposition of up to 1000mg/kg commercial TiO2 is unlikely to pose an immediate threat to isopod mortality and energy balance, reduced leaf feeding may have implications for the decomposition of plant material., (Copyright © 2016 Elsevier B.V. All rights reserved.)

We assessed the bioavailability of Ag from Ag nanoparticles (NPs), stabilized with polyvinylpyrrolidone (PVP), to terrestrial isopods which were exposed to 10, 100 and 1000 μg Ag NPs/g of dry food. Different Ag species were determined in the NP suspension that was fed to isopods: (i) total Ag by atomic absorption spectroscopy, (ii) the sum of Ag-PVP complexes and free Ag + by anodic stripping voltammetry at the bismuth-film electrode, and (iii) free Ag + by ion-selective potentiometry. The amounts of Ag species in the consumed food were compared to the masses of Ag accumulated in the isopod digestive glands. Our results show that all three Ag species (Ag NPs, Ag-PVP complexes and free Ag + ) could be the source of bioaccumulated Ag, but to various degrees depending on the exposure concentration and transformations in the digestive system. We provide a proof that (i) Ag NPs dissolve and Ag-PVP complexes dissociate in the isopod digestive tract; (ii) the concentration of free Ag + in the suspension offered to the test organisms is not the only measure of bioavailable Ag. The type of NP stabilizer along with the NP transformations in the digestive system needs to be considered in the creation of new computational models of the nanomaterial fate., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Biomolecular profiling with Fourier-Transform InfraRed Microscopy was performed to distinguish the Zn(2+)-mediated effects on the crustacean (Porcellio scaber) digestive glands from the ones elicited by the ZnO nanoparticles (NPs). The exposure to ZnO NPs or ZnCl2 (1500 and 4000 µg Zn/g of dry food) activated different types of metabolic pathways: some were found in the case of both substances, some only in the case of ZnCl2, and some only upon exposure to ZnO NPs. Both the ZnO NPs and the ZnCl2 increased the protein (∼1312 cm(-1); 1720-1485 cm(-1)/3000-2830 cm(-1)) and RNA concentration (∼1115 cm(-1)). At the highest exposure concentration of ZnCl2, where the effects occurred also at the organismal level, some additional changes were found that were not detected upon the ZnO NP exposure. These included changed carbohydrate (most likely glycogen) concentrations (∼1043 cm(-1)) and the desaturation of cell membrane lipids (∼3014 cm(-1)). The activation of novel metabolic pathways, as evidenced by changed proteins' structure (at 1274 cm(-1)), was found only in the case of ZnO NPs. This proves that Zn(2+) are not the only inducers of the response to ZnO NPs. Low bioavailable fraction of Zn(2+) in the digestive glands exposed to ZnO NPs further supports the role of particles in the ZnO NP-generated effects. This study provides the evidence that ZnO NPs induce their own metabolic responses in the subtoxic range.

The main goal of the study was to evaluate the avoidance behaviour of isopods (Porcellio scaber) to food or soil contaminated with different nanoparticles (NPs): Ag-NPs, sulfidized Ag-NPs (Ag 2 S-NPs) or CeO 2 -NPs. These NPs are characterized by different physiochemical properties, and antimicrobial and toxic potentials. Isopods were exposed in three scenarios: (i) 14 d feeding test where animals were fed solely on contaminated leaves; (ii) 14 d food selection test where leaves spiked with NPs were offered simultaneously with uncontaminated leaves; and (iii) 48 h soil avoidance test where animals could choose between uncontaminated and soil spiked with NPs. The isopods decreased feeding on Ag-NP contaminated food and clearly avoided contact with Ag-NP contaminated soil. Substantial accumulation of Ag in the body of isopods was found both in feeding and food selection test. This means that food selection might mitigate but could not prevent Ag accumulation in woodlice. In contrast, no such behavioural response of isopods was found for CeO 2 -NP. These data suggest that the presence of metal ions in the case of Ag-NPs may be the main reason for differential behaviour. Interestingly, moderate avoidance behaviour was observed also towards Ag 2 S-NPs although no Ag+ was detected in stock suspensions. This avoidance was not statistically significant and needs to be further explored. Behavioural test with isopods showed again their value in estimation of potential adverse effects of pollutants comparable to collembolans and earthworms. • Isopods evidently avoided food or soil treated with Ag-NPs. • Discrimination of food or soil contaminated with CeO2 was not prominent. • Food selection might mitigate but could not prevent Ag accumulation in isopods. • Avoidance test with isopods is a good tool to evaluate the contamination of soil. [ABSTRACT FROM AUTHOR]

Salinization of soil as the main cause for soil degradation is a global issue. Despite this, the data concerning the effects of different salts on terrestrial organisms are still missing. Our aim was to address the effects of four different salts (NaCl, KCl, NaNO 3 , and KNO 3 ) on terrestrial isopods Porcellio scaber. Two types of experiments were performed. In the first experiment, the isopods were exposed to 1, 2, and 5 g salt/kg dry leaf for 14 days and afterwards animal mortality, feeding activity, moult and growth were monitored. In the second experiment, a 48-h soil selection tests was done to investigate their preference/avoidance to certain salts. The feeding rate and growth efficiency of isopods decreased in a dose-dependent manner after 14 days exposure to KNO 3 and NaNO 3 . We suggest that nitrate (NO 3 − ) may be the predominant reason for these effects, because (i) the effects were only observed in the case of NO 3 − -salts, and (ii) K + and Na + induced no effects in the case of Cl − -salts where the concentrations of these two cations were even higher as in the case of NO 3 − salts. 48-h soil selection test showed that isopods were able to choose between NaCl dosed and unamended soil: the isopods preferred to spend time on NaCl spiked soil (up to 5 g salt/kg dry soil). In the case of KNO 3 and NaNO 3 no significant soil selection by isopods was found. In these two exposures isopods spent approximately 50% of their visits on both sides of the soil. The survival of isopods decreased in a dose independent manner when exposed to NaNO 3 , KNO 3 , and KCl. We conclude that NaNO 3 , KCl, and KNO 3 affect the isopods, while no effects were caused by NaCl under the exposure conditions of this study. This study implies that also other salts besides commonly investigated NaCl should be tested when the potential hazard of soil salinization to terrestrial organisms is in question. [ABSTRACT FROM AUTHOR]