325 research outputs found
Response to “traits and stress: keys to identify community effects of low levels of toxicants in test systems” by Liess and Beketov (2011)
Effects of the Veterinary Pharmaceutical Ivermectin in Indoor Aquatic Microcosms
The effects of the parasiticide ivermectin were assessed in plankton-dominated indoor microcosms. Ivermectin was applied once at concentrations of 30, 100, 300, 1000, 3000, and 10,000 ng/l. The half-life (dissipation time 50%; DT50) of ivermectin in the water phase ranged from 1.1 to 8.3 days. The lowest NOECcommunity that could be derived on an isolated sampling from the microcosm study by means of multivariate techniques was 100 ng/l. The most sensitive species in the microcosm study were the cladocerans Ceriodaphnia sp. (no observed effect concentration, NOEC = 30 ng/l) and Chydorus sphaericus (NOEC = 100 ng/l). The amphipod Gammarus pulex was less sensitive to ivermectin, showing consistent statistically significant reductions at the 1000-ng/l treatment level. Copepoda taxa decreased directly after application of ivermectin in the highest treatment but had already recovered at day 20 posttreatment. Indirect effects (e.g., increase of rotifers, increased primary production) were observed at the highest treatment level starting only on day 13 of the exposure phase. Cladocera showed the highest sensitivity to ivermectin in both standard laboratory toxicity tests as well as in the microcosm study. This study demonstrates that simple plankton-dominated test systems for assessing the effects of ivermectin can produce results similar to those obtained with large complex outdoor systems
Ecological impacts of time-variable exposure regimes to the fungicide azoxystrobin on freshwater communities in outdoor microcosms
This paper evaluates the effects of different time-varying exposure patterns of the strobilurin fungicide azoxystrobin on freshwater microsocosm communities. These exposure patterns included two treatments with a similar peak but different time-weighted average (TWA) concentrations, and two treatments with similar TWA but different peak concentrations. The experiment was carried out in outdoor microcosms under four different exposure regimes; (1) a continuous application treatment of 10 μg/L (CAT10) for 42 days (2), a continuous application treatment of 33 μg/L (CAT33) for 42 days (3), a single application treatment of 33 μg/L (SAT33) and (4) a four application treatment of 16 μg/L (FAT16), with a time interval of 10 days. Mean measured 42-d TWA concentrations in the different treatments were 9.4 μg/L (CAT10), 32.8 μg/L (CAT33), 14.9 μg/L (SAT33) and 14.7 μg/L (FAT16). Multivariate analyses demonstrated significant changes in zooplankton community structure in all but the CAT10 treated microcosms relative to that of controls. The largest adverse effects were reported for zooplankton taxa belonging to Copepoda and Cladocera. By the end of the experimental period (day 42 after treatment), community effects were of similar magnitude for the pulsed treatment regimes, although the magnitude of the initial effect was larger in the SAT33 treatment. This indicates that for long-term effects the TWA is more important for most zooplankton species in the test system than the peak concentration. Azoxystrobin only slightly affected some species of the macroinvertebrate, phytoplankton and macrophyte assemblages. The overall no observed ecologically adverse effect concentrations (NOEAEC) in this study was 10 µg/L
Rebuttal related to “Traits and Stress: Keys to identify community effects of low levels of toxicants in test systems” by Liess and Beketov (2011)
Identifying ecological production functions for use in ecosystem services-based environmental risk assessment of chemicals
This is the final version. Available from Elsevier via the DOI in this record. There is increasing research interest in the application of the ecosystem services (ES) concept in the environmental risk assessment of chemicals to support formulating and operationalising regulatory environmental protection goals and making environmental risk assessment more policy- and value-relevant. This requires connecting ecosystem structure and processes to ecosystem function and henceforth to provision of ecosystem goods and services and their economic valuation. Ecological production functions (EPFs) may help to quantify these connections in a transparent manner and to predict ES provision based on function-related descriptors for service providing species, communities, ecosystems or habitats. We review scientific literature for EPFs to evaluate availability across provisioning and regulation and maintenance services (CICES v5.1 classification). We found quantitative production functions for nearly all ES, often complemented with economic valuation of physical or monetary flows. We studied the service providing units in these EPFs to evaluate the potential for extrapolation of toxicity data for test species obtained from standardised testing to ES provision. A broad taxonomic representation of service providers was established, but quantitative models directly linking standard test species to ES provision were extremely scarce. A pragmatic way to deal with this data gap would be the use of proxies for related taxa and stepwise functional extrapolation to ES provision and valuation, which we conclude possible for most ES. We suggest that EPFs may be used in defining specific protection goals (SPGs), and illustrate, using pollination as an example, the availability of information for the ecological entity and attribute dimensions of SPGs. Twenty-five pollination EPFs were compiled from the literature for biological entities ranging from ‘colony’ to ‘habitat’, with 75% referring to ‘functional group’. With about equal representation of the attributes ‘function’, ‘abundance’ and ‘diversity’, SPGs for pollination therefore would seem best substantiated by EPFs at the level of functional group.European Chemical Industry Council Long-range Research Initiativ
The use of the multivariate Principal Response Curve (PRC) for community analysis: a case study on the effects of carbendazim on enchytraeids in Terrestrial Model Ecosystems (TME).
The effects of the fungicide carbendazim (formulation Derosal®) on enchytraeids were determined in Terrestrial Model Ecosystem (TME) tests. TMEs consisted of intact soil columns (diameter 17.5 cm; length 40 cm) taken from three grassland sites (Amsterdam (The Netherlands), Bangor (Wales, England) and Flörsheim (Germany)) or an arable site (Coimbra (Portugal)). Results for each TME site were evaluated using the multivariate Principal Response Curve (PRC) method. The resulting No-Observable Effect Concentrations (NOECs) for the community were compared with the NOECs generated by univariate statistical methods. Furthermore, the E
Assessing chemical risk within an ecosystem services framework: Implementation and added value
This is the final version. Available from Elsevier via the DOI in this record. An ecosystem services (ES) approach to chemical risk assessment has many potential advantages, but there are also substantial challenges regarding its implementation. We report the findings of a multi-stakeholder workshop that evaluated the feasibility of adopting an ES approach to chemical risk assessment using currently available tools and data. Also evaluated is the added value such an approach would bring to environmental decision making. The aim was to build consensus across disparate stakeholders and to co-produce a common understanding of the regulatory benefits and feasibility of implementing an ES approach in European chemicals regulation. Workshop discussions were informed by proof of concept studies and resulted in the development of a novel tiered framework for assessing chemical risk to ES delivery. There was consensus on the substantial added value of adopting an ES-based approach for regulatory decision making. Ecosystem services provide a common currency and a ‘unifying approach’ across environmental compartments, stressors and regulatory frameworks. The ES approach informs prioritisation of risk and remedial action and aids risk communication and risk management. It facilitates a more holistic assessment, enables ES trade-offs to be compared across alternative interventions, and supports comparative risk assessments and a socio-economic analysis of management options and decisions. Key to realising this added value is a shift away from using a single threshold value to categorise risk, towards a consideration of the exposure-effect distribution for individual ES of interest. Also required is the development of an integrated systems-level approach across regulatory frameworks and agreement on specific protection goals and scenarios for framing environmental risk assessments. The need to further develop tools for extrapolating toxicity data to service providers and ES delivery, including logic chains and ecological production functions, was highlighted. Also agreed was the need for methods and metrics for ES valuation to be used in assessing trade-offs.European Chemical Industry Counci
Effects of the fungicide metiram in outdoor freshwater microcosms: responses of invertebrates, primary producers and microbes
The ecological impact of the dithiocarbamate fungicide metiram was studied in outdoor freshwater microcosms, consisting of 14 enclosures placed in an experimental ditch. The microcosms were treated three times (interval 7 days) with the formulated product BAS 222 28F (Polyram®). Intended metiram concentrations in the overlying water were 0, 4, 12, 36, 108 and 324 μg a.i./L. Responses of zooplankton, macroinvertebrates, phytoplankton, macrophytes, microbes and community metabolism endpoints were investigated. Dissipation half-life (DT50) of metiram was approximately 1–6 h in the water column of the microcosm test system and the metabolites formed were not persistent. Multivariate analysis indicated treatment-related effects on the zooplankton (NOECcommunity = 36 μg a.i./L). Consistent treatment-related effects on the phytoplankton and macroinvertebrate communities and on the sediment microbial community could not be demonstrated or were minor. There was no evidence that metiram affected the biomass, abundance or functioning of aquatic hyphomycetes on decomposing alder leaves. The most sensitive populations in the microcosms comprised representatives of Rotifera with a NOEC of 12 μg a.i./L on isolated sampling days and a NOEC of 36 μg a.i./L on consecutive samplings. At the highest treatment-level populations of Copepoda (zooplankton) and the blue-green alga Anabaena (phytoplankton) also showed a short-term decline on consecutive sampling days (NOEC = 108 μg a.i./L). Indirect effects in the form of short-term increases in the abundance of a few macroinvertebrate and several phytoplankton taxa were also observed. The overall community and population level no-observed-effect concentration (NOECmicrocosm) was 12–36 μg a.i./L. At higher treatment levels, including the test systems that received the highest dose, ecological recovery of affected measurement endpoints was fast (effect period < 8 weeks)
The use of ecological models to assess the effects of a plant protection product on ecosystem services provided by an orchard
This is the final version. Available on open access from Elsevier via the DOI in this record The objective of this case study was to explore the feasibility of using ecological models for applying an ecosystem services-based approach to environmental risk assessment using currently available data and methodologies. For this we used a 5 step approach: 1) selection of environmental scenario, 2) ecosystem service selection, 3) development of logic chains, 4) selection and application of ecological models and 5) detailed ecosystem service assessment. The study system is a European apple orchard managed according to integrated pest management principles. An organophosphate insecticide was used as the case study chemical. Four ecosystem services are included in this case study: soil quality regulation, pest control, pollination and recreation. Logic chains were developed for each ecosystem service and describe the link between toxicant effects on service providing units and ecosystem services delivery. For the soil quality regulation ecosystem service, springtails and earthworms were the service providing units, for the pest control ecosystem service it was ladybirds, for the pollination ecosystem service it was honeybees and for the recreation ecosystem service it was the meadow brown butterfly. All the ecological models addressed the spatio-temporal magnitude of the direct effects of the insecticide on the service providing units and ecological production functions were used to extrapolate these outcomes to the delivery of ecosystem services. For all ecosystem services a decision on the acceptability of the modelled and extrapolated effects on the service providing units could be made using the protection goals as set by the European Food Safety Authority (EFSA). Developing quantitative ecological production functions for extrapolation of ecosystem services delivery from population endpoints remains one of the major challenges. We feel that the use of ecological models can greatly add to this development, although the further development of existing ecological models, and of new models, is needed for this.European Chemical Industry Counci
Midlife diagnosis of Refsum Disease in siblings with Retinitis Pigmentosa – the footprint is the clue: a case report
<p>Abstract</p> <p>Introduction</p> <p>Refsum disease is a potentially lethal and disabling condition associated with retinitis pigmentosa in which early treatment can prevent some of the systemic manifestations.</p> <p>Case presentation</p> <p>We present the cases of two brothers with a diagnosis of retinitis pigmentosa from childhood in whom Refsum disease was subsequently diagnosed midlife, after routine enquiry into hand and feet abnormalities. Subsequent treatment through dietary modification stabilised visual impairment and has prevented development of neurological complications to date.</p> <p>Conclusion</p> <p>It is therefore important to consider the diagnosis of Refsum disease in any patient with autosomal recessive or simplex retinitis pigmentosa, and to enquire about the presence of "unusual" feet or hands in such patients.</p
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