| 41. |
- Bundschuh, Mirco, et al.
(författare)
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Resilience in ecotoxicology: Toward a multiple equilibrium concept
- 2017
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Ingår i: Environmental Toxicology and Chemistry. - : Wiley. - 0730-7268 .- 1552-8618. ; 36, s. 2574-2580
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Forskningsöversikt (refereegranskat)abstract
- The term resilience describes stress-response patterns across scientific disciplines. In ecology, advances have been made to clearly define resilience based on underlying mechanistic assumptions. Engineering resilience (rebound) is used to describe the ability of organisms to recover from adverse conditions (disturbances), which is termed the rate of recovery. By contrast, the ecological resilience definition considers a systemic change, that is, when ecosystems reorganize into a new regime following disturbance. Under this new regime, structural and functional aspects change considerably relative to the previous regime, without recovery. In this context, resilience is an emergent property of complex systems. In the present study, we argue that both definitions and uses are appropriate in ecotoxicology, and although the differences are subtle, the implications and uses are profoundly different. We discuss resilience concepts in ecotoxicology, where the prevailing view of resilience is engineering resilience from chemical stress. Ecological resilience may also be useful for describing systemic ecological changes because of chemical stress. We present quantitative methods that allow ecotoxicologists and risk managers to assess whether an ecosystem faces an impending regime shift or whether it has already undergone such a shift. We contend that engineering and ecological resilience help to distinguish ecotoxicological responses to chemical stressors mechanistically and thus have implications for theory, policy, and application. (C) 2017 SETAC
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| 42. |
- Bundschuh, Mirco
(författare)
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Runoff of veterinary pharmaceuticals from arable and grassland-A comparison between predictions from model simulations and experimental studies
- 2016
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Ingår i: Agriculture, Ecosystems and Environment. - : Elsevier BV. - 0167-8809 .- 1873-2305. ; 218, s. 33-39
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Tidskriftsartikel (refereegranskat)abstract
- Veterinary pharmaceuticals (VPs) are routinely used in livestock breeding. As a consequence, high concentrations of such VPs can be found in liquid manure, which is often applied to arable crops and grassland. From the soil, the VPs may enter surface water bodies via edge-of-field runoff, representing a potential risk to aquatic ecosystems. In the present study, the worst-case runoff predictions obtained by the FOCUS step 3 modeling approach, which is recommended for environmental-risk assessment of VPs in Europe, were compared with fate data obtained from experimental plot studies involving both arable and grassland plots. Five VPs were selected comprising three sulfonamides (sulfadiazine, sulfadimidine, sulfamethoxazole) and two benzimidazoles (fiubendazole, fenbendazole). The respective concentrations in runoff were initially estimated using literature data for model parameterization. Subsequently, the scenarios were parameterized specifically for each experimental plot study performed, enabling a direct comparison of the model performance with the close-to-field relevant situation.Generally, substantial variations between the predicted and measured concentrations of VPs in the runoff were uncovered. Although the FOCUS prediction suggested higher concentrations than were actually measured in 65% of the cases, the runoff concentrations of VPs were underestimated in the remaining 35%. This frequent underestimation of runoff concentrations was primarily observed for the grassland plots (85% of the underestimated situations), whereas the FOCUS predictions largely overestimated the measured concentrations for the arable plots. More strikingly, when involving a difference between the measured and predicted concentrations of 10% as a validity criterion for the model, only one (out of a total of 17) runoff concentration among the five VPs (i.e., sulfadimidine) assessed in the seven scenarios fell within this tolerance margin. Thus, these results demonstrate the substantial uncertainties related to the use of the FOCUS surface water modeling approach for the prediction of VPs introduced with manure and their environmental risk. (C) 2015 Elsevier B.V. All rights reserved.
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| 43. |
- Bundschuh, Mirco
(författare)
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Structural and functional effects of a short-term pyrethroid pulse exposure on invertebrates in outdoor stream mesocosms
- 2018
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 610-611, s. 810-819
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Tidskriftsartikel (refereegranskat)abstract
- Agricultural land-use frequently results in short pulse exposures of insecticides such as pyrethroids in river systems, adversely affecting local invertebrate communities. In order to assess insecticide-induced effects, stream mesocosms are used within higher tier aquatic risk assessment. Regulatory acceptable concentrations (RACs) derived from those studies are often higher compared with tier 1 RACs. Hence, the present mesocosm study evaluates this aspect using a pulse exposure scenario typical for streams and the pyrethroid insecticide etofenprox. A 6-h pulse exposure with measured concentrations of 0.04, 0.3 and 5.3 mu g L-1 etofenprox was used. We considered abundance, drift and emergence of invertebrates as structural endpoints and the in situ-measured feeding rates of the isopod Asellus aquaticus as functional endpoint. Most prominent effects were visible at 5.3 mu g L-1 etofenprox which caused adverse effects of up to 100% at the individual and population level, as well as community structure alterations. Transient effects were observed for invertebrate drift (effect duration <= 24 h) and for the invertebrate community (9 days after exposure) at 0.3 mu g L-1 etofenprox. Furthermore, 0.04 mu g L-1 etofenprox affected the abundance of the mayfly Cloeon simile (decrease by 66%) and the feeding rate of A. aquaticus (decrease by 44%). Thus, implications for the functional endpoint leaf litter breakdown in heterotrophic ecosystems may be expected. A hypothetical RAC derived from the present mesocosm study (0.004 mu g L-1) is in line with the official tier 1 RAC (0.0044 mu g L-1) and thus shows that the present mesocosm study did not result in a higher RAC. (C) 2017 Elsevier B.V. All rights reserved.
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| 44. |
- Bundschuh, Mirco
(författare)
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Synthesis, characterization, and ecotoxicity of CeO2 nanoparticles with differing properties
- 2016
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Ingår i: Journal of Nanoparticle Research. - : Springer Science and Business Media LLC. - 1388-0764 .- 1572-896X. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- CeO2 nanoparticles with various characteristics find an increasing number of applications in the electronic, medical, and other industries and are therefore likely released in the environment. This calls for investigations linking the physicochemical properties of these particles with their potential environmental impacts. In this study, CeO2 nanoparticle powders were prepared using three different precursors [Ce(NO3)(3), CeCl3, and Ce(CH3COO)(3)] and annealing temperatures (300, 500, and 700 degrees C). This procedure resulted in nine different types of nanoparticles with differing size (5-90 nm), morphology, surface Ce3+/Ce4+ ratio, and slightly different crystal structures as characterized using transmission electron microscopy, dynamic light scattering, X-ray photoelectron spectroscopy, and X-ray diffraction measurements with Rietveld refinement. These CeO2 nanoparticles underwent toxicity testing at concentrations up to 64 mg L-1 using Daphnia magna. Toxic effects were observed for three particle types with EC50 values between 5 and 64 mg L-1. No clear correlation was observed between the physicochemical properties (size, shape, oxygen occupancy, Ce3+/Ce4+ ratio) of the nanoparticles and their toxicity. However, toxicity was correlated with the amount of Ce remaining suspended in the test medium after 24 h. This indicated that toxic effects may depend on the colloidal stability of CeO2 nanoparticles during the first day of exposure. Therefore, being readily suspended and remaining stable for several days in the aquatic media increases the likelihood that CeO2 nanoparticles will cause unwanted adverse effects.
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| 45. |
- Bundschuh, Mirco, et al.
(författare)
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The mode of bioturbation triggers pesticide remobilization from aquatic sediments
- 2016
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Ingår i: Ecotoxicology and Environmental Safety. - : Elsevier BV. - 0147-6513 .- 1090-2414. ; 130, s. 171-176
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Tidskriftsartikel (refereegranskat)abstract
- After their release into the aquatic environment, contaminants may - depending on the physicochemical properties - adsorb to sediments. From there these contaminants can either be buried or remobilised by abiotic factors (e.g., resuspension) as well as by the bioturbating activity of sediment dwelling invertebrates. Little is, however, know about the effects of bioturbation on the fate of pesticides. Therefore, the present study quantified the impact of the bioturbation mode of benthic invertebrate species (bio-diffusor vs. bio-irrigation), the invertebrate density (i.e. 0-8 individuals per replicate), and the substance inherent properties (i.e. hydrophobicity, water solubility) on the remobilization of sediment-associated pesticides in a laboratory-based set-up over 13 days. We found that both the bioturbation mode (i.e., species identity) and species density, as well as pesticide properties (i.e., hydrophobicity) affected the direction and magnitude of remobilisation of sediment-bound pesticides. The oligochaeta Lumbriculus variegatus showed a density-dependent effect on the remobilization of lindane to the water phase, whereas those with the amphipod Monoporeia affinis and larvae of the midge Chironomus riparius did not. Although these findings show that sediments not per definition are a sink for pesticides, the rates of pesticide remobilization are limited. This observation, thus, suggests that the risk for aquatic communities posed by the remobilization of pesticides from the sediment due to bioturbation is low. (C) 2016 Published by Elsevier Inc.
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| 46. |
- Bundschuh, Mirco
(författare)
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Transient effects following peak exposures towards pesticides - An explanation for the unresponsiveness of in situ measured functional variables
- 2017
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Ingår i: Environmental Pollution. - : Elsevier BV. - 0269-7491 .- 1873-6424. ; 231, s. 1393-1397
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Tidskriftsartikel (refereegranskat)abstract
- Invertebrate-mediated leaf litter decomposition is frequently used to assess stress-related implications in stream ecosystem integrity. In situ measures such as the mass loss from leaf bags or the feeding of caged invertebrates deployed for days or weeks may, however, fail to detect transient effects due to recovery or compensatory mechanisms. We assessed the relevance of transient effects using the peak exposure towards an insecticide (i.e., etofenprox) as a model scenario at three levels of complexity. These were 1) the assessment of the decomposition realised by invertebrate communities in stream mesocosms over 21 days via leaf bags, 2) 7-days lasting in situ bioassays quantifying the leaf consumption of Gammarus fossarum, and 3) a laboratory experiment determining the daily feeding rate of the same species over 7 days. Etofenprox did not trigger a significantly altered decomposition by invertebrate communities during the leaf bag assay, while in situ bioassays detected a significant reduction in gammarids' feeding rate at the highest tested concentration. The laboratory bioassay suggests that observed mismatches might be explained by recovery and post-exposure compensation. As leaf-shredding invertebrates are likely in a vulnerable state following transient effects, biomonitoring for implications of peak exposures and other pulsed stress events must happen at an adequate temporal resolution. (C) 2017 Elsevier Ltd. All rights reserved.
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| 47. |
- Bundschuh, Mirco
(författare)
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Wastewater treatment plant effluents as source of cosmetic polyethylene microbeads to freshwater
- 2017
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 188, s. 25-31
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Tidskriftsartikel (refereegranskat)abstract
- Microplastics in the environment are either a product of the fractionation of larger plastic items or a consequence of the release of microbeads, which are ingredients of cosmetics, through wastewater treatment plant (WWTP) effluents. The aim of this study was to estimate the amount of microbeads that may be released by the latter pathways to surface waters using Ljubljana, Slovenia as a case study. For this purpose, microbeads contained in cosmetics were in a first step characterized for their physical properties and particle size distribution. Subsequently, daily emission of microbeads from consumers to the sewerage system, their fate in biological WWTPs and finally their release into surface waters were estimated for Ljubljana. Most of the particles found in cosmetic products were <100 mu m. After application, microbeads are released into sewerage system at an average rate of 15.2 mg per person per day. Experiments using a lab-scale sequencing batch biological WWTP confirmed that on average 52% of microbeads are captured in activated sludge. Particle size analyses of the influent and effluent confirmed that smaller particles (up to 60-70 mu m) are captured within activated sludge while bigger particles were detected in the effluent. Applying these data to the situation in Ljubljana indicates that about 112,500,000 particles may daily be released into the receiving river, resulting in a microbeads concentration of 21 particles/m(3). Since polyethylene particles cannot be degraded and thus likely accumulate, the data raise concerns about potential effects in aquatic ecosystems in future. (C) 2017 Elsevier Ltd. All rights reserved.
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| 48. |
- Caldenby, Claes, 1946
(författare)
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Session 10-reinventing public institutions
- 2018
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Ingår i: Proceedings of the 15th International Docomomo Conference - Metamorphosis: The Continuity of Change, IDC 2018. - 9789899964549 ; 2018, s. 343-344
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Konferensbidrag (refereegranskat)
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| 49. |
- Carlsson, Julia, et al.
(författare)
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Opportunites for Integrated Landscape Planning : the Broker, the Arena, the Tool
- 2017
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Ingår i: Landscape Online. - 1865-1542. ; 55, s. 1-20
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Tidskriftsartikel (refereegranskat)abstract
- As an integrated social and ecological system, the forest landscape includes multiple values. The need for a landscape approach in land use planning is being increasingly advocated in research, policy and practice. This paper explores how institutional conditions in the forest policy and management sector can be developed to meet demands for a multifunctional landscape perspective. Departing from obstacles recognised in collaborative planning literature, we build an analytical framework which is operationalised in a Swedish context at municipal level. Our case illustrating this is Vilhelmina Model Forest, where actual barriers and opportunities for a multiple-value landscape approach are identified through 32 semi-structured interviews displaying stakeholders’ views on forest values, ownership rights and willingness to consider multiple values, forest policy and management premises, and collaboration. As an opportunity to overcome the barriers, we suggest and discuss three key components by which an integrated landscape planning approach could be realized in forest management planning: the need for a landscape coordinator (broker), the need for a collaborative forum (arena), and the development of the existing forest management plan into an advanced multifunctional landscape plan (tool).
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| 50. |
- Cascone, Claudia
(författare)
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Optical sensors in drinking water production : Towards automated process control in relation to natural organic matter
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Access to safe and clean drinking water is a basic human right (A/RES/64/292). In Sweden, large drinking water treatment plants use mainly surface water as water source. The long-term trend of increasing natural organic matter (NOM) in boreal and north European surface waters negatively affects the overall performance of the treatment processes. To address this issue, sensors are increasingly used as a tool for real-time analysis of water quality providing early warning of potential contamination and decision support for process control.In this thesis, absorbance- and fluorescence-based sensors were used to estimate dissolved organic matter (DOM) concentrations in two Swedish rivers prior to managed aquifer recharge (MAR) and their accuracy was compared (Paper I and IV). The possibility of coupling a coagulation treatment with MAR was explored at laboratory-scale. Two pilot-scale experiments using granular activated carbon filtration were carried out to optimise DOM removal (Paper II). A recent method for molecular DOM analysis was tested to investigate the effect of ozone on low molecular weight compounds. An open-source Python toolbox called “AbspectroscoPY” was developed to pre-process the large amount of absorbance-based sensor data and compute a range of spectral metrics from the time-series data. This allowed a preliminary identification of variability in the spectrophotometric profiles of treated water as a step forward toward automated early warning systems (Paper III). An algorithm for turbidity compensation of the raw absorbance spectra was added (Paper IV). This thesis contributes to an increased knowledge on NOM removal in water treatment using high frequency sensor data from optical sensors.
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