Auswirkungen der Pflanzenschutzmittel-Belastung auf Lebensgemeinschaften in Fließgewässern des landwirtschaftlich geprägten Raumes

In die ökologische Risikoabschätzung von Pflanzenschutzmitteln (PSM) sollten zukünftig Erfassungen von toxischen Effekten im Freiland einbezogen werden. Ziel des Projektes war, Dosis-Wirkungs-Beziehungen zwischen der PSM-Belastung und aquatischen Lebensgemeinschaften in kleinen Fließgewässern durch Freilanduntersuchungen zu beschreiben. An 14 Gewässern in Niedersachsen und Brandenburg wurden neben anderen Faktoren die PSM-Belastung und die Makroinvertebratenbesiedelung aufgenommen. In Wasserproben aus 11 der 14 Gewässer wurden Belastungen mit PSM verschiedener Wirkstoffe nachgewiesen. Stichlinge (Gasterosteus aculeatus L.) aus mit Parathion belasteten Gewässern zeigten eine erniedrigte Aktivität von Butyryl-Cholinesterase (BChE) im Muskelgewebe. Im Laborversuch wurde gezeigt, daß bereits geringe Parathion-Konzentrationen bei sehr kurzzeitiger Exposition die BChE-Aktivität in Stichlingen partiell zu hemmen vermögen. Eine Literaturauswertung ergab, daß sich Makroinvertebraten-Ordnungen nach ihrer relativen Empfindlichkeit gegenüber organischen Toxinen unterscheiden und in ein entsprechendes Rangordnungssystem einordnen lassen. Zur Datenauswertung wurde ein Index zur Beschreibung von Zönosenveränderungen durch Toxine gebildet (Sensitivity-Recovery-Index, SR-Index). In den PSM-belasteten Gewässern wurde eine geringere Artenzahl physiologisch empfindlicher Invertebraten sowie ein geringerer Abundanzanteil von Arten mit einem mehrjährigen Entwicklungszyklus gefunden. Zwischen der Gesamttoxizität (TUsum) der in den Gewässern nachgewiesenen PSM und dem Abundanzanteil der empfindlichen Arten sowie dem SR-Index bestanden lineare Zusammenhänge. Die Ergebnisse zeigten, daß bereits Parathion-Konzentrationen von weniger als 1 µg/l bei kurzzeitiger Kontamination eine hohe Bioverfügbarkeit aufweisen. Weiterhin wurde gezeigt, daß auch gering konzentrierte PSM-Belastungen Lebensgemeinschaften in Fließgewässern chronisch verändern können, sofern die Belastung regelmäßig wiederkehrt.Evaluations on toxic effects of pesticides in the field are to be included in future ecological risk assessments. Aim of this project was to determine the dose-response relationships between pesticide contamination and aquatic communities in small streams through fieldwork research. Fourteen streams in Niedersachsen and Brandenburg were investigated to record pesticide contamination, the macroinvertebrate community structure and other factors. Water samples from 11 of the 14 streams showed pesticide contamination. Sticklebacks (Gasterosteus aculeatus L.) present in parathion-contaminated streams revealed reduced Butyryl-Cholinesterase (BChE) activity in their muscle tissue. Laboratory experiments indicated that already low parathion concentrations during short-term contamination inhibited BChE activity. A literature evaluation revealed that macroinvertebrate orders can be distinguished by their relative sensitivity to organic toxins using a ranking system. A Sensitivity-Recovery-Index (SR-Index) evaluated data by describing the community changes resulting from toxin contamination. At pesticide contaminated sites lower numbers of sensitive species and lower relative abundance of species with a long reproduction cycle were found. There was a linear correlation between total toxicity (TUsum) of pesticides detected, between relative abundance of sensitive species and the SR-Index. Results showed that even parathion concentrations lower than 1µg/L exhibited strong bioavailability following short-term contamination. Moreover, pesticide contamination in low concentrations can affect and alter the stream community on a long term scale providing contamination occurs regularly. The observed dose-response relationship verifies that results from field investigations can be used to derive quality measures and objectives to control agricultural pesticide application

5-Point programme for sustainable plant protection

Abstract This position paper intends to stimulate a profound rethinking of contemporary agricultural practice. We criticise the current intensity of chemical plant protection in Germany as ecologically unsustainable and thus threatening the achievement of key targets of environmental protection and nature conservation policies. In the first part of the paper, we provide background information on the use of plant protection products (PPP) in German agriculture, the role of agricultural policy, European pesticide legislation, the principles of and framework for environmental risk assessment and risk management of PPP, as well as environmental effects of PPP. The second part is presented against the backdrop of the European “Sustainable Use Directive” (2009/128/EC). This directive requires that “Member States shall adopt National Action Plans to set up their quantitative objectives, targets, measures, and timetables to reduce risks and impacts of pesticide use on human health and the environment and to encourage the development and introduction of integrated pest management and of alternative approaches or techniques to reduce dependency on the use of pesticides.” Reflecting on the corresponding debate in Germany, we suggest the following five key principles for a sustainable use of PPP and provide recommendations for their implementation: (1) minimising use; (2) identifying, quantifying, and communicating risks; (3) optimising risk management; (4) compensating for unavoidable effects; (5) internalising external costs

Ecological Models in Support of Regulatory Risk Assessments of Pesticides: Developing a Strategy for the Future [Short Communication]

This brief communication reports on the main findings of the LEMTOX workshop, held from September 9 to 12,2007, at the Helmholtz Centre for Environmental Research (UFZ) in Leipzig, Germany. The workshop brought together a diverse group of stakeholders from academia, regulatory authorities, contract research organizations, and industry, representing Europe, the United States, and Asia, to discuss the role of ecological modeling in risk assessments of pesticides, particularly under the European regulatory framework. The following questions were addressed: What are the potential benefits of using ecological models in pesticide registration and risk assessment? What obstacles prevent ecological modeling from being used routinely in regulatory submissions? What actions are needed to overcome the identified obstacles? What recommendations should be made to ensure good modeling practice in this context? The workshop focused exclusively on population models, and discussion was focused on those categories of population models that link effects on individuals (e.g., survival, growth, reproduction, behavior) to effects on population dynamics. The workshop participants concluded that the overall benefits of ecological modeling are that it could bring more ecology into ecological risk assessment, and it could provide an excellent tool for exploring the importance of, and interactions among, ecological complexities. However, there are a number of challenges that need to be overcome before such models will receive wide acceptance for pesticide risk assessment, despite having been used extensively in other contexts (e.g., conservation biology). The need for guidance on Good Modeling Practice (on model development, analysis, interpretation, evaluation, documentation, and communication), as well as the need for case studies that can be used to explore the added value of ecological models for risk assessment, were identified as top priorities. Assessing recovery potential of exposed nontarget species and clarifying the ecological relevance of standard laboratory test results are two areas for which ecological modeling may be able to provide considerable benefits

Better define beta–optimizing MDD (minimum detectable difference) when interpreting treatment-related effects of pesticides in semi-field and field studies

The minimum detectable difference (MDD) is a measure of the difference between the means of a treatment and the control that must exist to detect a statistically significant effect. It is a measure at a defined level of probability and a given variability of the data. It provides an indication for the robustness of statistically derived effect thresholds such as the lowest observed effect concentration (LOEC) and the no observed effect concentration (NOEC) when interpreting treatment-related effects on a population exposed to chemicals in semi-field studies (e.g., micro-/mesocosm studies) or field studies. MDD has been proposed in the guidance on tiered risk assessment for plant protection products in edge of field surface waters (EFSA Journal 11(7):3290, 2013), in order to better estimate the robustness of endpoints from such studies for taking regulatory decisions. However, the MDD calculation method as suggested in this framework does not clearly specify the power which is represented by the beta-value (i.e., the level of probability of type II error). This has implications for the interpretation of experimental results, i.e., the derivation of robust effect values and their use in risk assessment of PPPs. In this paper, different methods of MDD calculations are investigated, with an emphasis on their pre-defined levels of type II error-probability. Furthermore, a modification is suggested for an optimal use of the MDD, which ensures a high degree of certainty for decision-makers

CREAM: A European project on mechanistic effect models for ecological risk assessment of chemicals

Examples that clearly demonstrate the power of mechanistic effect models (MEMs) for risk assessment are urgently needed, and industry, academia, and regulatory authorities across Europe need scientists that are trained in MEMs, principles of ecotoxicology, and regulatory risk assessment. To meet these needs, Chemical Risk Effects Assessment Models (CREAM), a European project including 20 Ph.D. and three postdoctoral projects, has been launched for September 2009 and will last for 4 years. CREAM is a “Marie Curie Initial Training Network (ITN)” funded by the European Commission within the 7th Framework Programme. ITNs are part of the commission’s “People” Programme and focus on mobility and first-class training of early stage researchers. CREAM is very likely the largest joint project worldwide developing MEMs for risk assessment of chemicals. The aims and scope of CREAM are: 1. Formulate and test guidance for Good Modeling Practice (GMoP) that ensures transparent and reliable decision support for chemical risk assessment. 2. Develop a suite of well-tested and validated mechanistic ecological effect models for a range of organisms and ecosystems relevant for chemical risk assessments. 3. Provide world-class training for the next generation of modelers, emphasizing transparency and rigorous model evaluation as core elements of models for decision support

Assessing in-field pesticide effects under European regulation and its implications for biodiversity: a workshop report

Abstract Background Biodiversity loss is particularly pronounced in agroecosystems. Agricultural fields cover about one-third of the European Union and are crucial habitats for many species. At the same time, agricultural fields receive the highest pesticide input in European landscapes. Non-target species, including plants and arthropods, closely related to targeted pests, are directly affected by pesticides. Direct effects on these lower trophic levels cascade through the food web, resulting in indirect effects via the loss of food and habitat for subsequent trophic levels. The overarching goals of the European pesticide legislation require governments to sufficiently consider direct and indirect effects on plants and arthropods when authorising pesticides. This publication provides an overview of a workshop's findings in 2023 on whether the current pesticide risk assessment adequately addresses these requirements. Results Effects due to in-field exposure to pesticides are currently not assessed for plants and inadequately assessed for arthropods, resulting in an impairment of the food web support and biodiversity. Deficiencies lie within the risk assessment, as defined in the terrestrial guidance document from 2002. To overcome this problem, we introduce a two-step assessment method feasible for risk assessors, that is to determine (i) whether a pesticide product might have severe impacts on plants or arthropods and (ii) whether these effects extend to a broad taxonomic spectrum. When each step is fulfilled, it can be concluded that the in-field exposure of the pesticide use under assessment could lead to unacceptable direct effects on non-target species in-field and thus subsequent indirect effects on the food web. While our primary focus is to improve risk assessment methodologies, it is crucial to note that risk mitigation measures, such as conservation headlands, exist in cases where risks from in-field exposure have been identified. Conclusions We advocate that direct and indirect effects caused by in-field exposure to pesticides need to be adequately included in the risk assessment and risk management as soon as possible. To achieve this, we provide recommendations for the authorities including an evaluation method. Implementing this method would address a major deficiency in the current in-field pesticide risk assessment and ensure better protection of biodiversity

The lowland stream monitoring dataset (KgM, Kleingewässer-Monitoring) 2018, 2019

Plant protection products in the environment are partly responsible for the progressive loss of biodiversity. The mostly insufficient ecological status of surface waters is often explained by habitat degradation and excessive nutrient input. But what role do plant protection products play in this context? The Kleingewässermonitoring (KgM) project provides a worldwide unique quantitative assessment of the impact of pesticides from diffuse agricultural sources on small and medium-sized streams. The dataset comprises 124 monitoring stream sections all over Germany covering a wide pollution gradient where consistent measurements were carried out in 2018 and 2019 during the major pesticide application period from April to July. These measurements include event-driven sampling to record surface rainfall-induced short-term peak concentrations in addition to regular grab sampling of pesticides and a wide range of other pollutants resulting in more than 1,000 water samples. All further relevant anthropogenic and environmental parameters reigning ecological stream quality were recorded comprehensively (morphological and stream bed structure, temperature, flow velocity, dissolved oxygen, pH, catchment land use, stream profile). The dataset also contains effect monitoring data featuring sampled invertebrate communities and bioassay analyses of water samples. The data enables an assessment of pesticide exposure and related effects as well as the analysis of complex causal relationships in streams