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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]

Organophosphate pesticide diazinon is a specific inhibitor of acetylcholinesterase (AChE), which is a common neurotoxicity biomarker in environmental studies. In honeybees, AChE exists in two forms having different physiological roles, one existing as a soluble form and the other as membrane-bound. In most studies AChE activity has been analysed without paying considerable attention to different forms of AChE. In this study, we exposed honeybees Apis mellifera carnica for 10 days to diazinon via oral exposure and analysed the total AChE activities in salt soluble (SS) and detergent soluble (DS) fractions. We assumed that SS fraction would preferentially contain the soluble AChE, but the DS fraction would contain only membrane AChE. On the contrary, our results showed that SS and DS fractions both contain soluble and membrane AChE and the latter has considerably higher activity. Despite this we obtained a differential response of AChE activity in SS and DS fractions when exposed to diazinon. The head/thorax AChE activity in DS fraction decreased, while the head/thorax AChE activity in SS fraction increased at sublethal concentrations. The AChE activity in honeybee hemolymph shown here for the first time is a salt soluble enzyme. Its activity remained unaltered after diazinon treatment. In conclusion, we provide evidence that varying results regarding AChE activity alterations upon stressor exposure are obtained when extracted through different procedures. In further environmental studies with honeybees this differential response of AChE activity should be given considerable attention because this affects the outcome of ecotoxicity study. [ABSTRACT FROM AUTHOR]

We investigated the effects of a commercial pigment grade rutile TiO 2 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 14 days exposure to up to 1000 mg TiO 2 per kg dry leaves (mg/kg) under any experimental scenario. However, in the field tests, isopods consumption of TiO 2 -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 TiO 2 , suggesting that rather than sensing the TiO 2 on the leaves directly, the isopods under open-air and barn exposure responded to altered attractiveness and/or palatability of the TiO 2 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 1000 mg/kg commercial TiO 2 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. [ABSTRACT FROM AUTHOR]

Exposure of beneficial soil organisms to chemical mixtures is of great concern and can result in unexpected deleterious consequences. We investigated the effects of concurrent soil contamination with monensin, a veterinary pharmaceutical and feed additive, and copper, on earthworm copper uptake and reproductive success. The animals were exposed for 14 or 28 days to both substances and the results showed that the Cu body burden of earthworms increases in the presence of monensin. The harmful effects of Cu on earthworm cocoon production were considerably higher when monensin was also present in the soil. To localise the copper in earthworm tissues, histological staining was performed using two different dyes (rubeanic acid and 5-4-( p -dimethylaminobenzylidene)-rhodanine). Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was used to quantify the Cu levels in the tissues. Cu was found predominantly in the gut wall. The Cu content in the body wall was at least ten times lower compared to the gut, but was proportional to the level of soil contamination. Concurrent soil contamination with monensin and copper resulted in higher earthworm Cu levels and in decreased reproductive success of these important soil decomposers. [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]

Dialdehyde cellulose nanofibrils (CNF) and nanocrystals (CNC) were prepared via periodate oxidation (CNF/CNC-ox) and subsequently functionalized with hexamethylenediamine (HMDA) via a Schiff-base reaction, resulting in partially crosslinked micro-sized (0.5–10 μm) particles (CNF/CNC-ox-HMDA) with an aggregation and sedimentation tendency in an aqueous media, as assessed by Dynamic Light Scattering and Scanning Electron Microscopy. The antibacterial efficacy, aquatic in vivo (to Daphnia magna) and human in vitro (to A594 lung cells) toxicities, and degradation profiles in composting soil of all forms of CNF/CNC were assessed to define their safety profile. CNF/CNC-ox-HMDA exhibited higher antibacterial activity than CNF/CNC-ox and higher against Gram-positive S. aureus than Gram-negative E. coli , yielding a bacteria reduction of >90 % after 24 h of exposure at the minimum (≤2 mg/mL), but potentially moderately/aquatic and low/human toxic concentrations (≥50 mg/L). The presence of anionic, un/protonated amino-hydrophobized groups in addition to unconjugated aldehydes of hydrodynamically smaller (<1 μm) CNC-ox-HMDA increased the reduction of both bacteria to log 9 at ≥4 mg/mL and their bactericidal activity. While only CNF/CNC-ox can be considered as biosafe and up to >80 % biodegradable within 24 weeks, this process was inhibited for the CNF/CNC-ox-HMDA. This indicated their different stability, application and disposal after use (composting vs. recycling). • Dialdehyde CNF/CNC (CNF/CNC-ox) were conjugated with hexamethylenediamine (HMDA). • Both forms inhibit bacteria growth at non-toxic (≤2 mg/mL) concentration. • CNF/CNC-ox-HMDA interact more strongly and diversely with the bacterial cell walls. • Hydrodynamically smaller (≤1 μm) CNC-ox-HMDA reduce bacteria to log 9 at ≥4 mg/mL. • Only CNF/CNC-ox can be considered as biosafe and ecotoxicology acceptable. [ABSTRACT FROM AUTHOR]

Biomolecular profiling with Fourier-Transform InfraRed Microscopy was performed to distinguish the Zn2+-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 ZnCl2increased 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 Zn2+are not the only inducers of the response to ZnO NPs. Low bioavailable fraction of Zn2+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. [ABSTRACT FROM AUTHOR]