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Berlin Brandenburg

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  • 1
    Language: English
    In: Proceedings of the National Academy of Sciences of the United States of America, 05 May 2015, Vol.112(18), pp.5750-5
    Description: Compared with nutrient levels and habitat degradation, the importance of agricultural pesticides in surface water may have been underestimated due to a lack of comprehensive quantitative analysis. Increasing pesticide contamination results in decreasing regional aquatic biodiversity, i.e., macroinvertebrate family richness is reduced by ∼30% at pesticide concentrations equaling the legally accepted regulatory threshold levels (RTLs). This study provides a comprehensive metaanalysis of 838 peer-reviewed studies (〉2,500 sites in 73 countries) that evaluates, for the first time to our knowledge on a global scale, the exposure of surface waters to particularly toxic agricultural insecticides. We tested whether measured insecticide concentrations (MICs; i.e., quantified insecticide concentrations) exceed their RTLs and how risks depend on insecticide development over time and stringency of environmental regulation. Our analysis reveals that MICs occur rarely (i.e., an estimated 97.4% of analyses conducted found no MICs) and there is a complete lack of scientific monitoring data for ∼90% of global cropland. Most importantly, of the 11,300 MICs, 52.4% (5,915 cases; 68.5% of the sites) exceeded the RTL for either surface water (RTLSW) or sediments. Thus, the biological integrity of global water resources is at a substantial risk. RTLSW exceedances depend on the catchment size, sampling regime, and sampling date; are significantly higher for newer-generation insecticides (i.e., pyrethroids); and are high even in countries with stringent environmental regulations. These results suggest the need for worldwide improvements to current pesticide regulations and agricultural pesticide application practices and for intensified research efforts on the presence and effects of pesticides under real-world conditions.
    Keywords: Agriculture ; Biodiversity ; Global Surface Waters ; Insecticide Contamination ; Regulatory Risk Assessment ; Environmental Monitoring -- Methods ; Insecticides -- Analysis ; Water Pollutants, Chemical -- Analysis
    ISSN: 00278424
    E-ISSN: 1091-6490
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  • 2
    Language: English
    In: Science of the Total Environment, 15 October 2018, Vol.639, pp.516-525
    Description: The decades-long agricultural use of insecticides resulted in frequent contamination of surface waters globally regularly posing high risks for the aquatic biodiversity. However, the concentration levels of individual insecticide compounds have by now not been compiled and reported using global scale data, hampering our knowledge on the insecticide exposure of aquatic ecosystems. Here, we specify measured insecticide concentrations (MICs, comprising in total 11,300 water and sediment concentrations taken from a previous publication) for 28 important insecticide compounds covering four major insecticide classes. Results show that organochlorine and organophosphate insecticides, which dominated the global insecticide market for decades, have been detected most often and at highest concentration levels in surface waters globally. In comparison, MICs of the more recent pyrethroids and neonicotinoids were less often reported and generally at lower concentrations as a result of their later market introduction and lower application rates. An online insecticide classification calculator (ICC; available at: ) is provided in order to enable the comparison and classification of prospective MICs with available global insecticide concentrations. Spatial analyses of existing data show that most MICs were reported for surface waters in North America, Asia and Europe, whereas highest concentration levels were detected in Africa, Asia and South America. An evaluation of water and sediment MICs showed that theoretical organic carbon-water partition coefficients (K ) determined in the laboratory overestimated K values based on actual field concentrations by up to a factor of more than 20, with highest deviations found for highly sorptive pyrethroids. Overall, the comprehensive compilation of insecticide field concentrations presented here is a valuable tool for the classification of future surface water monitoring results and serves as important input data for more field relevant toxicity testing approaches and pesticide exposure and risk assessment schemes.
    Keywords: Pesticides ; Surface Water Exposure ; Monitoring ; Global Survey ; Koc ; Environmental Sciences ; Biology ; Public Health
    ISSN: 0048-9697
    E-ISSN: 1879-1026
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  • 3
    Language: English
    In: Science of the Total Environment, 01 March 2016, Vol.545-546, pp.171-183
    Description: Regulatory risk assessment considers vegetated buffer strips as effective risk mitigation measures for the reduction of runoff-related pesticide exposure of surface waters. However, apart from buffer strip widths, further characteristics such as vegetation density or the presence of erosion rills are generally neglected in the determination of buffer strip mitigation efficacies. This study conducted a field survey of fruit orchards (average slope 3.1–12.2%) of the Lourens River catchment, South Africa, which specifically focused on the characteristics and attributes of buffer strips separating orchard areas from tributary streams. In addition, in-stream and erosion rill water samples were collected during three runoff events and GIS-based modeling was employed to predict losses of pesticides associated with runoff. The results show that erosion rills are common in buffer strips (on average 13 to 24 m wide) of the tributaries (up to 6.5 erosion rills per km flow length) and that erosion rills represent concentrated entry pathways of pesticide runoff into the tributaries during rainfall events. Exposure modeling shows that measured pesticide surface water concentrations correlated significantly (R = 0.626; p 〈 0.001) with runoff losses predicted by the modeling approach in which buffer strip width was set to zero at sites with erosion rills; in contrast, no relationship between predicted runoff losses and in-stream pesticide concentrations were detected in the modeling approach that neglected erosion rills and thus assumed efficient buffer strips. Overall, the results of our study show that erosion rills may substantially reduce buffer strip pesticide retention efficacies during runoff events and suggest that the capability of buffer strips as a risk mitigation tool for runoff is largely overestimated in current regulatory risk assessment procedures conducted for pesticide authorization.
    Keywords: Risk Assessment ; Runoff ; Monitoring ; Exposure Modeling ; Field Survey ; South Africa ; Environmental Sciences ; Biology ; Public Health
    ISSN: 0048-9697
    E-ISSN: 1879-1026
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  • 4
    Language: English
    In: Environmental Science and Pollution Research, 2015, Vol.22(24), pp.19632-19647
    Description: Pesticides constitute an integral part of high-intensity European agriculture. Prior to their authorization, a highly elaborated environmental risk assessment is mandatory according to EU pesticide legislation, i.e., Regulation (EC) No. 1107/2009. However, no field data-based evaluation of the risk assessment outcome, i.e., the regulatory acceptable concentrations (RACs), and therefore of the overall protectiveness of EU pesticide regulations exists. We conducted here a comprehensive meta-analysis using peer-reviewed literature on agricultural insecticide concentrations in EU surface waters and evaluated associated risks using the RACs derived from official European pesticide registration documents. As a result, 44.7 % of the 1566 cases of measured insecticide concentrations (MICs) in EU surface waters exceeded their respective RACs. It follows that current EU pesticide regulations do not protect the aquatic environment and that insecticides threaten aquatic biodiversity. RAC exceedances were significantly higher for insecticides authorized using conservative tier-I RACs and for more recently developed insecticide classes, i.e., pyrethroids. In addition, we identified higher risks, e.g., for smaller surface waters that are specifically considered in the regulatory risk assessment schemes. We illustrate the shortcomings of the EU regulatory risk assessment using two case studies that contextualize the respective risk assessment outcomes to field exposure. Overall, our meta-analysis challenges the field relevance and protectiveness of the regulatory environmental risk assessment conducted for pesticide authorization in the EU and indicates that critical revisions of related pesticide regulations and effective mitigation measures are urgently needed to substantially reduce the environmental risks arising from agricultural insecticide use.
    Keywords: Pesticide ; Surface water ; Europe ; Risk assessment ; Regulation (EC) No. 1107/2009 ; Regulatory acceptable concentration ; Meta-analysis
    ISSN: 0944-1344
    E-ISSN: 1614-7499
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  • 5
    Language: English
    In: Environmental Monitoring and Assessment, 2013, Vol.185(8), pp.6295-6310
    Description: Due to the specific modes of action and application patterns of agricultural insecticides, the insecticide exposure of agricultural surface waters is characterized by infrequent and short-term insecticide concentration peaks of high ecotoxicological relevance with implications for both monitoring and risk assessment. Here, we apply several fixed-interval strategies and an event-based sampling strategy to two generalized and two realistic insecticide exposure patterns for typical agricultural streams derived from FOCUS exposure modeling using Monte Carlo simulations. Sampling based on regular intervals was found to be inadequate for the detection of transient insecticide concentrations, whereas event-triggered sampling successfully detected all exposure incidences at substantially lower analytical costs. Our study proves that probabilistic risk assessment (PRA) concepts in their present forms are not appropriate for a thorough evaluation of insecticide exposure. Despite claims that the PRA approach uses all available data to assess exposure and enhances risk assessment realism, we demonstrate that this concept is severely biased by the amount of insecticide concentrations below detection limits and therefore by the sampling designs. Moreover, actual insecticide exposure is of almost no relevance for PRA threshold level exceedance frequencies and consequential risk assessment outcomes. Therefore, we propose a concept that features a field-relevant ecological risk analysis of agricultural insecticide surface water exposure. Our study quantifies for the first time the environmental and economic consequences of inappropriate monitoring and risk assessment concepts used for the evaluation of short-term peak surface water pollutants such as insecticides.
    Keywords: Insecticides ; Surface water exposure ; Monitoring ; Risk assessment
    ISSN: 0167-6369
    E-ISSN: 1573-2959
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  • 6
    In: Journal of Computer‐Mediated Communication, May 2015, Vol.20(3), pp.278-294
    Description: Computer‐mediated communication among university students with different cultural backgrounds has become widespread. In this study, we examine how undergraduates ( = 130) react to cultural cues when responding to an e‐mail request for cooperation sent by a peer. Participants rated the sender's personality and stated their willingness to help. In the inquiry, 2 types of cultural cues were varied, resulting in a 2 × 2 factorial design: ethnicity (German vs. Chinese name) and communication style (Western vs. Asian). Results showed that participants aligned their responses to the communication style; however, the ethnicity cue influenced the wording of their response, their perception of the sender's personality and their willingness to help. Results are discussed regarding communication accommodation and social judgment theories.
    Keywords: Intercultural Communication ; Computer‐Mediated Communication ; Lexical Alignment ; Higher Education ; Helping Behavior ; Social Judgment
    ISSN: 1083-6101
    E-ISSN: 1083-6101
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  • 7
    Language: English
    In: Research in Higher Education, 2012, Vol.53(8), pp.888-904
    Description: Relating students’ evaluations of teaching (SETs) to student learning as an approach to validate SETs has produced inconsistent results. The present study tested the hypothesis that the strength of association of SETs and student learning varies with the criteria used to indicate student learning. A multisection validity approach was employed to investigate the association of SETs and two different criteria of student learning, a multiple-choice test and a practical examination. Participants were N  = 883 medical students, enrolled in k  = 32 sections of the same course. As expected, results showed a strong positive association between SETs and the practical examination but no significant correlation between SETs and multiple-choice test scores. Furthermore, students’ subjective perception of learning significantly correlated with the practical examination score whereas no relation was found for subjective learning and the multiple choice test. It is discussed whether these results might be due to different measures of student learning varying in the degree to which they reflect teaching effectiveness.
    Keywords: Students’ evaluations of teaching ; SETs ; Teaching effectiveness ; Student learning
    ISSN: 0361-0365
    E-ISSN: 1573-188X
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  • 8
    Language: English
    In: Bulletin of Environmental Contamination and Toxicology, 2016, Vol.96(5), pp.563-564
    Description: To access, purchase, authenticate, or subscribe to the full-text of this article, please visit this link: http://dx.doi.org/10.1007/s00128-016-1788-5 Byline: Sebastian Stehle (1), Ralf Schulz (1) Author Affiliation: (1) Institute for Environmental Sciences, University Koblenz-Landau, Fortstra[sz]e 7, 76829, Landau, Germany Article History: Registration Date: 23/03/2016 Received Date: 08/02/2016 Accepted Date: 22/03/2016 Online Date: 28/03/2016 Article note: Electronic supplementary material The online version of this article (doi: 10.1007/s00128-016-1788-5) contains supplementary material, which is available to authorized users.
    Keywords: Water Pollution ; Water Resources ; Insecticides;
    ISSN: 0007-4861
    E-ISSN: 1432-0800
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  • 9
    Language: English
    In: Science of the Total Environment, 01 January 2018, Vol.610-611, pp.810-819
    Description: 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 μg L etofenprox was used. We considered abundance, drift and emergence of invertebrates as structural endpoints and the in situ-measured feeding rates of the isopod as functional endpoint. Most prominent effects were visible at 5.3 μg L 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 μg L etofenprox. Furthermore, 0.04 μg L etofenprox affected the abundance of the mayfly (decrease by 66%) and the feeding rate of (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 μg L ) is in line with the official tier 1 RAC (0.0044 μg L ) and thus shows that the present mesocosm study did not result in a higher RAC.
    Keywords: Functional Endpoint ; Aquatic Guidance Document ; Community ; Drift ; Emergence ; Environmental Sciences ; Biology ; Public Health
    ISSN: 0048-9697
    E-ISSN: 1879-1026
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  • 10
    Language: English
    In: Psychology Learning & Teaching, September 2014, Vol.13(3), pp.205-217
    Description: In this study the relationship between intended course objectives and teaching effectiveness was investigated. Teaching effectiveness was indexed through student evaluations of teaching (SETs) and lecturer self-evaluations (LSEs), with a focus on course evaluation. Rated learning of intended course objectives was derived by two parallel questionnaires administered to 1647 students and 84 lecturers in 84 psychology courses. In particular, lecturers rated the importance of 11 course objectives for their course, while students rated their perceived achievement throughout the course according to the same 11 course objectives. Corresponding importance and achievement ratings were used to calculate separate measures of students' achievement of intended and unintended course objectives. Results show that students' perceived achievement of intended course objectives was associated with better SETs and LSEs. No association with SETs or LSEs were found for students' perceived achievement of unintended course objectives. These findings support the importance of having clear course objectives for effective student learning.
    Keywords: Psychology
    E-ISSN: 1475-7257
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