Impact of polyethylene microbeads on the floating freshwater plant duckweed Lemna minor.

Microplastics (MP), small plastic particles below 5 mm, have become one of the central concerns of environmental risk assessment. Microplastics are continuously being released into the aquatic environment either directly through consumer products or indirectly through fragmentation of larger plastic materials. The aim of our study was to investigate the effect of polyethylene microbeads from cosmetic products on duckweed (Lemna minor), a freshwater floating plant.

Comparative study of acetylcholinesterase and glutathione S-transferase activities of closely related cave and surface Asellus aquaticus (Isopoda: Crustacea).

The freshwater isopod crustacean Asellus aquaticus has recently been developed as an emerging invertebrate cave model for studying evolutionary and developmental biology. Mostly morphological and genetic differences between cave and surface A. aquaticus populations have been described up to now, while scarce data are available on other aspects, including physiology.

Uptake and effects of microplastic textile fibers on freshwater crustacean Daphnia magna.

Microplastic fibers (MP) from textile weathering and washing are increasingly being recognized as environmental pollutants. The majority of studies on the bioavailability and effects of microplastic focused on small polystyrene spherical plastic particles, while less data are available for fibers and for other materials besides polystyrene. We investigated the ingestion and effects of ground polyethylene terephthalate (PET) textile microfibers (length range: 62-1400 μm, width 31-528 μm, thickness 1-21.

The role of PVP in the bioavailability of Ag from the PVP-stabilized Ag nanoparticle suspension.

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.

In field conditions, commercial pigment grade TiO2 was not harmful to terrestrial isopods but reduced leaf litter fragmentation.

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.

Multilaboratory evaluation of 15 bioassays for (eco)toxicity screening and hazard ranking of engineered nanomaterials: FP7 project NANOVALID.

Within EU FP7 project NANOVALID, the (eco)toxicity of 7 well-characterized engineered nanomaterials (NMs) was evaluated by 15 bioassays in 4 laboratories. The highest tested nominal concentration of NMs was 100 mg/l. The panel of the bioassays yielded the following toxicity order: Ag > ZnO > CuO > TiO2 > MWCNTs > SiO2 > Au.

A case study to optimise and validate the brine shrimp Artemia franciscana immobilisation assay with silver nanoparticles: The role of harmonisation.

Brine shrimp Artemia sp. has been recognised as an important ecotoxicity and nanotoxicity test model organism for salt-rich aquatic environments, but currently there is still no harmonised testing protocol which would ensure the comparable results for hazard identification. In this paper we aimed to design the harmonised protocol for nanomaterial toxicity testing using Artemia franciscana and present a case study to validate the protocol with silver nanoparticles (AgNPs).

The impact of humic acid on chromium phytoextraction by aquatic macrophyte Lemna minor.

Studies assessing chromium phytoextration from natural waters rarely consider potential implications of chromium speciation in the presence of ubiquitous humic substances. Therefore, the present study investigated the influence of environmentally relevant concentration of humic acid (TOC = 10 mg L(-1)) on chromium speciation (Cr = 0.15 mg L(-1)) and consequently on phytoextraction by aquatic macrophyte duckweed Lemna minor.

An interlaboratory comparison of nanosilver characterisation and hazard identification: Harmonising techniques for high quality data.

Within the FP7 EU project NanoValid a consortium of six partners jointly investigated the hazard of silver nanoparticles (AgNPs) paying special attention to methodical aspects that are important for providing high-quality ecotoxicity data. Laboratories were supplied with the same original stock dispersion of AgNPs. All partners applied a harmonised procedure for storage and preparation of toxicity test suspensions.

FTIR microscopy reveals distinct biomolecular profile of crustacean digestive glands upon subtoxic exposure to ZnO nanoparticles.

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)).

High surface adsorption properties of carbon-based nanomaterials are responsible for mortality, swimming inhibition, and biochemical responses in Artemia salina larvae.

We investigated the effects of three different carbon-based nanomaterials on brine shrimp (Artemia salina) larvae. The larvae were exposed to different concentrations of carbon black, graphene oxide, and multiwall carbon nanotubes for 48 h, and observed using phase contrast and scanning electron microscopy. Acute (mortality) and behavioural (swimming speed alteration) responses and cholinesterase, glutathione-S-transferase and catalase enzyme activities were evaluated.

The hazard assessment of nanostructured CeO₂-based mixed oxides on the zebrafish Danio rerio under environmentally relevant UV-A exposure.

The effect of nanomaterials on biota under realistic environmental conditions is an important question. However, there is still a lack of knowledge on how different illumination conditions alter the toxicity of some photocatalytic nanomaterials. We have investigated how environmentally relevant UV-A exposure (intensity 8.

Bioavailability of cobalt and iron from citric-acid-adsorbed CoFe2O4 nanoparticles in the terrestrial isopod Porcellio scaber.

The aim of this study was to determine whether citric acid adsorbed onto cobalt ferrite (CoFe2O4) nanoparticles (NPs) influences the bioavailability of their constituents Co and Fe. Dissolution of Co and Fe was assessed by two measures: (i) in aqueous suspension using chemical analysis, prior to application onto the food of test organisms; and (ii) in vivo, measuring the bioavailability in the model terrestrial invertebrate (Porcellio scaber, Isopoda, Crustacea). The isopods were exposed to citric-acid-adsorbed CoFe2O4 NPs for 2 weeks, and tissue accumulation of Co and Fe was assessed.

Hindered disulfide bonds to regulate release rate of model drug from mesoporous silica.

With the advancement of drug delivery systems based on mesoporous silica nanoparticles (MSNs), a simple and efficient method regulating the drug release kinetics is needed. We developed redox-responsive release systems with three levels of hindrance around the disulfide bond. A model drug (rhodamine B dye) was loaded into MSNs' mesoporous voids.

Antioxidant responses and whole-organism changes in Daphnia magna acutely and chronically exposed to endocrine disruptor bisphenol A.

Bisphenol A (BPA) is a well known endocrine disruptor. Significantly less is known about its ability to induce antioxidant defense and oxidative stress in aquatic organisms. This is an interesting subject because BPA can act both as a prooxidant (induces the formation of reactive oxygen species) and an antioxidant.

Upon exposure to Cu nanoparticles, accumulation of copper in the isopod Porcellio scaber is due to the dissolved Cu ions inside the digestive tract.

The fate of nanoparticles in organisms is of significant interest. In the current work, we used a test system with terrestrial isopods (Porcellio scaber) fed with food spiked with Cu NPs or soluble Cu salt for 14 days. Two different doses were used for spiking to yield final concentrations of 2000 and 5000 μg Cu/g dry food.

Effects of four CeO2 nanocrystalline catalysts on early-life stages of zebrafish Danio rerio and crustacean Daphnia magna.

Effects of four different nanocrystalline CeO(2)-based catalysts on crustaceans Daphnia magna and early-life stages of zebrafish Danio rerio were studied. Pure CeO(2) and CuO-CeO(2) mixed oxides with a nominal 10, 15 and 20 mol.% CuO content were tested.

The link between antioxidant enzymes catalase and glutathione S-transferase and physiological condition of a control population of terrestrial isopod (Porcellio scaber).

The aim of this work was to investigate if the activities of catalase and glutathione S-transferase in a control population of terrestrial isopods (Porcellio scaber) are correlated with the physiological condition of the isopods. For this purpose, the activities of these enzymes were analysed in isopods from a stock population and in parallel, the physiological condition of the same specimens was assessed using a histological approach based on epithelial thickness and lipid droplets. We found a correlation between antioxidant enzymes and the physiological condition of the isopods.

Assessment of landfill leachate toxicity reduction after biological treatment.

In the present article, the efficiency of biological treatment of landfill leachates was evaluated by implementation of physicochemical characterisation and a complex toxicity assessment. An array of toxicity tests using bacterium Vibrio fischeri, alga Desmodesmus subspicatus, crustacean Daphnia magna, and embryo of fish Danio rerio, as well as unconventional methods using biochemical biomarkers (protein content, enzymes cholinesterase, and glutathione-S-transferase), were employed. Toxicity of leachates varied depending on the season of collection in relation to their different physicochemical characteristics.

Ecotoxicity of nanosized TiO2. Review of in vivo data.

This report presents an exhaustive literature review of data on the effect of nanoparticulate TiO(2) on algae, higher plants, aquatic and terrestrial invertebrates and freshwater fish. The aim, to identify the biologically important characteristics of the nanoparticles that have most biological significance, was unsuccessful, no discernable correlation between primary particle size and toxic effect being apparent. Secondary particle size and particle surface area may be relevant to biological potential of nanoparticles, but insufficient confirmatory data exist.

Toxicity of abamectin to the terrestrial isopod Porcellio scaber (Isopoda, Crustacea).

To determine effects of the antiparasitic veterinary drug abamectin on the isopod Porcellio scaber, animals were exposed for 21 days to Lufa 2.2 soil spiked at concentrations of 3-300 mg/kg dry soil. After exposure, abamectin residues in the isopods were analysed using a novel analytical method.

Zinc bioaccumulation in a terrestrial invertebrate fed a diet treated with particulate ZnO or ZnCl2 solution.

A number of reports on potential toxicity of nanoparticles are available, but there is still a lack of knowledge concerning bioaccumulation. The aim of this work was to investigate how different sources of zinc, such as uncoated and unmodified ZnO nanoparticles, ZnCl(2) in solution, and macropowder ZnO influence the bioaccumulation of this metal in the terrestrial isopod Porcellio scaber. After exposure to different sources of Zn in the diet, the amount of assimilated Zn in whole body, the efficiency of zinc assimilation, and bioaccumulation factors (BAFs) were assessed.

Hazardous potential of manufactured nanoparticles identified by in vivo assay.

New products of nanotechnologies, including nanoparticles, need to be assessed according to their biological reactivity and toxic potential. Given the large number of diverse nanomaterials, a tiered approach is favoured. The aim of our work presented here is to elaborate an in vivo assay with terrestrial invertebrates (Porcellio scaber), which could serve as a first step of hazard identification of nanoparticles.

Hazard identification of imidacloprid to aquatic environment.

The use of a very effective insecticide against sucking pests, neonicotinoid imidacloprid, has been increasing extensively. For this reason elevated concentrations are expected in aquatic environment. Despite this fact, there is still a lack of data available on its possible risk for the environment.

Biochemical biomarkers in environmental studies--lessons learnt from enzymes catalase, glutathione S-transferase and cholinesterase in two crustacean species.

Background, Aim And Scope: For reliable environmental risk assessment of pollutants, knowledge on the effects at different levels of biological organisation is needed. During the early days of biomarker research in environmental studies approximately two decades ago, biochemical biomarkers were considered as the most promising tool for such purposes. Among these, three enzymes have often been studied: catalase (CAT), glutathione S-transferase (GST) and cholinesterase (ChE).