Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2020
Abstract
No abstract has been registered
Authors
Claire CoutrisAbstract
No abstract has been registered
Authors
Anastasia Georgantzopoulou Claire Coutris Kuria Ndungu Christian Vogelsang Patricia Almeida Carvalho Ana Catarina Almeida Ailbhe MackenAbstract
The majority of nanomaterials (NMs) used in commercial applications are likely to enter the wastewater stream and reach wastewater treatment plants (WWTP). Studies have shown high association of NMs with sewage sludge therefore soils can be a sink for NM pollution making terrestrial organisms vulnerable. NMs undergo transformations in different environmental matrices leading to altered behaviour, bioavailability and subsequent toxicity that can differ from the pristinepristine material. The NM transformation and the potential hazard they pose in these compartments are poorly understood. The aim of the study was to elucidate (i) the behaviour of Ag and TiO2 NMs in sewage sludge and sludge amended-soil and (ii) the subsequent effects of transformed NMs on the coelomocytes of the earthworm E. fetida.Spherical polyvinylpyrrolidone (PVP)-coated Ag nanoparticles (Ag NPs, 25 nm) and uncoated TiO2 NPs (anatase, 5 nm primary size, NM-101,JRC) were used in this study. Two types of sludge were used for the exposures, one from a municipal WWTP (Oslo, Norway), and another from a lab-scale WWTP simulating biological wastewater treatment processes continuously dosed during 5 weeks with well-characterised Ag and TiO2 NPs. Earthworms (adults E. fetida) were exposed to LUFA 2.2 soil amended with sewage sludge at two application rates: 20 t ha-1 (maximum recommended application rate in Europe), and 3 times this application rate, i.e. 60 t ha-1 (worst-case scenario). After 12 and 39 days, coelomocytes were isolated from exposed earthworms, and effects on cell population, metabolic activity, lysosomal integrity and reactive oxygen species (ROS) formation were assessed. Characterization of NMs in the sludge amended-soil and soil elutriates, in whole earthworms and coelomocytes isolated from exposed earthworms, was carried out at the beginning (day 0), during (day 12) and the end (day 39) of the exposure period, using inductively coupled plasma-mass spectrometry (ICP-MS) and single-particle (sp)-ICP-MS. Dose and exposure time-dependent effects were observed, with an alteration in the cell composition of coelomocytes, increase in ROS formation and decrease in lysosomal membrane integrity being more pronounced at the highest exposure concentration. The importance of taking NM transformation into account and the sensitivity of the E. fetida coelomocytes as a model to study the effects of transformed NMs in vitro are discussed.
Abstract
The current study provides an in vivo analysis of the production of reactive oxygen species (ROS) and oxidative stress in the nematode Caenorhabditis elegans following exposure to EU reference silver nanoparticles NM300K and AgNO3. Induction of antioxidant defenses was measured through the application of a SOD-1 reporter, and the HyPer and GRX biosensor strains to monitor changes in the cellular redox state. Both forms of Ag resulted in an increase in sod-1 expression, elevated H2O2 levels and an imbalance in the cellular GSSG/GSH redox status. Microscopy analysis of the strains revealed that AgNO3 induced ROS-related effects in multiple tissues, including the pharynx, intestinal cells and muscle tissues. In contrast, NM300K resulted in localized ROS production and oxidative stress, specifically in tissues surrounding the intestinal lumen. This indicates that Ag from AgNO3 exposure was readily transported across the whole body, while Ag or ROS from NM300K exposure was predominantly confined within the luminal tissues. Concentrations resulting in an increase in ROS production and changes in GSSG/GSH ratio were in line with the levels associated with observed physiological toxic effects. However, sod-1 was not induced at the lowest Ag concentrations, although reprotoxicity was seen at these levels. While both forms of Ag caused oxidative stress, impaired development, and reprotoxicity, the results suggest different involvement of ROS production to the toxic effects of AgNO3 versus NM300K.
Authors
Claire CoutrisAbstract
No abstract has been registered
Authors
Claire CoutrisAbstract
No abstract has been registered
Authors
Anastasia Georgantzopoulou Julia Farkas Kuria Ndungu Claire Coutris Patricia Almeida Carvalho Andy M Booth Ailbhe MackenAbstract
In this study, the effects of aged Ag and TiO2 nanoparticles (NPs), individually and as a mixture, in wastewater relative to their pristine counterparts on the development of the copepod nauplii (Tisbe battagliai) were investigated. NP behavior in synthetic wastewater and seawater was characterized during aging and exposure. A delayed development and subsequent mortality were observed after 6 days of exposure to aged Ag NPs, with a twofold decrease in EC50 (316 μg/L) compared to pristine NPs (EC50 640 μg/L) despite the similar dissolved Ag concentrations measured for aged and pristine Ag NPs (441 and 378 μg/L, respectively). In coexposures with TiO2 NPs, higher dissolved Ag levels were measured for aged NPs (238.3 μg/L) relative to pristine NPs (98.57 μg/L). Coexposure resulted in a slight decrease (15%) in the Ag NP EC50 (270 μg/L) with a 1.9-fold increase in the Ag NP retained within the organisms after depuration (2.82% retention) compared to Ag NP single exposures as measured with sp-ICP− MS, suggesting that the particles are still bioavailable despite the heteroaggregation observed between Ag, Ti NPs, and wastewater components. This study shows that the presence of TiO2 NPs can affect the stability and toxicity of Ag NPs in complex media that cannot be predicted solely based on ionic, total, or nanoparticulate concentrations, and the need for studying NP interactions in more complex matrices is highlighted.
Abstract
No abstract has been registered
Authors
Karin Juul HesselsøeAbstract
No abstract has been registered
Authors
Karin Juul HesselsøeAbstract
No abstract has been registered