Search

To characterize the potential for exposure of amphibian terrestrial life stages to plant protection products (PPP), we studied the occurrence and habitat use of adult and metamorph common frogs (Rana temporaria) and common toads (Bufo bufo) in an agricultural landscape in Germany. The four selected study sites were breeding ponds with approximately 80% agricultural land within a 1‐km radius. Adults were monitored by radio tracking for two years, and metamorph numbers were assessed for one summer using pitfall traps alongside drift fences. The results demonstrate that adults were rarely present in arable fields at any of the sites (overall 0.5% and 4% of total observations for frogs and toads, respectively). Metamorph captures in arable fields were more variable, ranging from 1.2% to 38.8% (frogs) and from 0.0% to 26.1% (toads) across study sites. Unsurprisingly, most captures in arable fields for both toad and frog metamorphs occurred at the site where the pond was completely surrounded by arable fields. Overall, the presence of adult amphibians in arable fields was limited and, for the metamorphs, occurred primarily when crops were denser and PPP spray interception higher. Diurnal hiding behavior was observed with the highest activity recorded at night, further reducing the risk of dermal exposure from direct PPP overspraying. In addition, it appeared that alternative habitats, such as woody structures or water bodies in the broader surrounding area, were preferred by the animals over the arable areas. The use of buffer zones around water bodies in agricultural areas would be an effective risk mitigation measure to protect terrestrial adults and metamorphs residing there and would reduce spray drift entry into water bodies during PPP application. It is hoped that these results will contribute to the discussion of risk assessment and mitigation options for amphibians. Integr Environ Assess Manag 2024;20:2218–2230. © 2024 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). Key Points: Relevant potential exposure for both adult and metamorph anuran amphibians (i.e., common frogs and toads) on agricultural land was assessed.The movement and behavior of both adult and metamorph common frogs and common toads exhibited a preference for nonarable habitats and reduced potential for exposure.Landscape management is an option to protect and support amphibian populations effectively. [ABSTRACT FROM AUTHOR]

The toxicity and ecotoxicity of pesticide active ingredients are evaluated by a number of standardized test methods using vertebrate animals. These standard test methods are required under various regulatory programs for the registration of pesticides. Over the past two decades, additional test methods have been developed with endpoints that are responsive to endocrine activity and subsequent adverse effects. This article examines the available test methods and their endpoints that are relevant to an assessment of endocrine‐disrupting properties of pesticides. Furthermore, the article highlights how weight‐of‐evidence approaches should be applied to determine whether an adverse response in (eco)toxicity tests is caused by an endocrine mechanism of action. The large number of endpoints in the current testing paradigms for pesticides make it unlikely that endocrine activity and adversity is being overlooked. Integr Environ Assess Manag 2023;19:1089–1109. © 2023 Bayer CropScience and The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). Key Points: Current testing paradigms for pesticides include numerous endpoints addressing endocrine activity and adversity.A weight‐of‐evidence evaluation of test results is essential to assessing potential endocrine activity and/or adverse effects resulting from endocrine activity.The large number of endpoints in the current testing paradigms for pesticides make it unlikely that endocrine activity and adversity is being overlooked. [ABSTRACT FROM AUTHOR]

Many regulations are beginning to explicitly require investigation of a chemical's endocrine‐disrupting properties as a part of the safety assessment process for substances already on or about to be placed on the market. Different jurisdictions are applying distinct approaches. However, all share a common theme requiring testing for endocrine activity and adverse effects, typically involving in vitro and in vivo assays on selected endocrine pathways. For ecotoxicological evaluation, in vivo assays can be performed across various animal species, including mammals, amphibians, and fish. Results indicating activity (i.e., that a test substance may interact with the endocrine system) from in vivo screens usually trigger further higher‐tier in vivo assays. Higher‐tier assays provide data on adverse effects on relevant endpoints over more extensive parts of the organism's life cycle. Both in vivo screening and higher‐tier assays are animal‐ and resource‐intensive and can be technically challenging to conduct. Testing large numbers of chemicals will inevitably result in the use of large numbers of animals, contradicting stipulations set out within many regulatory frameworks that animal studies be conducted as a last resort. Improved strategies are urgently required. In February 2020, the UK's National Centre for the 3Rs and the Health and Environmental Sciences Institute hosted a workshop ("Investigating Endocrine Disrupting Properties in Fish and Amphibians: Opportunities to Apply the 3Rs"). Over 50 delegates attended from North America and Europe, across academia, laboratories, and consultancies, regulatory agencies, and industry. Challenges and opportunities in applying refinement and reduction approaches within the current animal test guidelines were discussed, and utilization of replacement and/or new approach methodologies, including in silico, in vitro, and embryo models, was explored. Efforts and activities needed to enable application of 3Rs approaches in practice were also identified. This article provides an overview of the workshop discussions and sets priority areas for follow‐up. Integr Environ Assess Manag 2022;18:442–458. © 2021 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). KEY POINTS: In vivo screening and higher‐tier assays to evaluate a chemical's potential endocrine‐disrupting properties and potential impacts on ecosystems are animal‐ and resource‐intensive and can be technically challenging to conduct.There has been much recent work to develop new approach methodologies (NAMs)—in silico and in vitro approaches—that can be applied in this space.An understanding of the opportunities and challenges with the current in vivo approaches, coupled with the ongoing efforts to expand the development, use, and application of NAMs, will help focus short‐ and long‐term goals.International, multisector science‐based activities provide the framework to improve ecological safety as it relates to compounds with endocrine‐disrupting properties. [ABSTRACT FROM AUTHOR]

The adverse outcome pathway (AOP) concept was developed to describe the linkage of events starting with chemical exposure to an apical effect, across levels of biological organization. In an AOP, the MIE is causally related to the AO through a series of key events (KEs) linked by key-event relationships (KERs). [Extracted from the article]

Recommendations for Reducing the USE of Fish and Amphibians in Endocrine-Disruption Testing of Biocides and Plant Protection Products in Europe Criteria for determining the endocrine-disrupting (ED) properties of biocide (European Union [EU] Regulation 2017/2100) and plant protection product (PPP) active substances (EU Regulation 2018/605) entered into force on 6 June and 10 November 2018, respectively. In the present article, we estimate the number of fish and amphibians required for ED testing, based on registered PPPs and biocides in Europe. 1 Estimated number of animals required for ED testing of registered pesticide and biocide active substances, based on range-finding and definitive testing, and adjusted for failure rates. [Extracted from the article]

The European Commission intends to protect vertebrate wildlife populations by regulating plant protection product (PPP) active substances that have endocrine‐disrupting properties with a hazard‐based approach. In this paper we consider how the Commission's hazard‐based regulation and accompanying guidance can be operationalized to ensure that a technically robust process is used to distinguish between substances with adverse population‐level effects and those for which it can be demonstrated that adverse effects observed (typically in the laboratory) do not translate into adverse effects at the population level. Our approach is to use population models within the adverse outcome pathway framework to link the nonlinear relationship between adverse effects at the individual and population levels in the following way: (1) use specific protection goals for focal wildlife populations within an ecosystem services framework; (2) model the effects of changes in population‐related inputs on focal species populations with individual‐based population models to determine thresholds between negligible and nonnegligible (i.e., adverse) population‐level effects; (3) compare these thresholds with the relevant endpoints from laboratory toxicity tests to determine whether they are likely to be exceeded at hazard‐based limits or the maximum tolerated dose/concentration from the experimental studies. If the population threshold is not exceeded, then the substance should not be classified as an endocrine disruptor with population‐relevant adversity unless there are other lines of evidence within a weight‐of‐evidence approach to challenge this. We believe this approach is scientifically robust and still addresses the political and legal requirement for a hazard‐based assessment. Integr Environ Assess Manag 2019;15:278–291. © 2018 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC) Key Points: In this paper we consider how the European Commission's hazard‐based Plant Protection Product Regulation can be operationalized to distinguish between substances with adverse population‐level effects and those for which observed adverse effects do not translate into adverse population‐level effects.Our approach is to use population models within the adverse outcome pathways framework to link the nonlinear relationship between adverse effects at the individual and population levels.Only if the population threshold is exceeded should the active substance be classified as an endocrine disruptor with population‐relevant adversity, unless this classification is challenged by other lines of evidence (e.g., from field studies) within a weight‐of‐evidence approach.We believe this approach is scientifically robust and addresses the political and legal requirement for a hazard‐based assessment. [ABSTRACT FROM AUTHOR]

The article explores several factors to consider in determining laboratory studies' population relevance in assessing wildlife population stability as a protection goal in exotoxicology. Topics include the need to ensure the stability of wildlife populations, the use of laboratory studies in ecological risk assessment, and the population relevance of an endpoint. Also discussed are the developments in predictive ecotoxicology and adverse outcome pathways.

ABSTRACT Endocrine-disrupting substances (EDS) may have certain biological effects including delayed effects, multigenerational effects, and may display nonmonotonic dose-response (NMDR) relationships that require careful consideration when determining environmental hazards. Endocrine disrupting substances can have specific and profound effects when exposure occurs during sensitive windows of the life cycle (development, reproduction). This creates the potential for delayed effects that manifest when exposure has ceased, possibly in a different life stage. This potential underscores the need for testing in appropriate (sensitive) life stages and full life cycle designs. Such tests are available in the Organisation for Economic Co-operation and Development (OECD) tool box and should be used to derive endpoints that can be considered protective of all life stages. Similarly, the potential for effects to be manifest in subsequent generations (multigenerational effects) has also been raised as a potential issue in the derivation of appropriate endpoints for EDS. However, multigenerational studies showing increasing sensitivity of successive generations are uncommon. Indeed this is reflected in the design of new higher tier tests to assess endocrine active substances (EAS) that move to extended one-generation designs and away from multi-generational studies. The occurrence of NMDRs is also considered a limiting factor for reliable risk assessment of EDS. Evidence to date indicates NMDRs are more prevalent in in vitro and mechanistic data, not often translating to adverse apical endpoints that would be used in risk assessment. A series of steps to evaluate NMDRs in the context of endocrine hazard and risk assessment procedures is presented. If careful consideration of delayed, multigenerational effects and NMDRs is made, it is feasible to assess environmental endocrine hazards and derive robust apical endpoints for risk assessment procedures ensuring a high level of environmental protection. Integr Environ Assess Manag 2017;13:293-301. © 2016 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC) [ABSTRACT FROM AUTHOR]

The article focuses on a research related to reduction in number of fish in bioconcentraion testing and identification of the related barriers. Topics discussed include bioconcentration tests being conducted according to Organization for Economic Co-operation and Development (OECD) guideline, use of 1-concentration approach for the research and amendment of OECD guideline permitting for testing of 1 concentration and guidelines of the U.S. Environmental Protection Agency.

This paper describes the basis for a water-only acute chironomid toxicity test guideline using first-instar larvae. The method is based on the OECD test guidelines for the acute Daphnia sp. immobilization test and the long-term tests with Chironomus sp., reflecting the common test procedures currently used by the European agrochemical industry. Development of this guideline proposal is important under the European Plant Protection Products Directive (91/414/EEC), under which an insect species may be required to be tested, particularly for certain insecticides, for which Daphnia sp. may not be representative of the sensitivity of nontarget aquatic invertebrates. Chironomus sp. is a freshwater insect currently used in different international test guidelines. Because their ready availability as a test organism, with culturing conditions and certain test methods already established, Chironomus sp. is regarded as a suitable additional freshwater invertebrate species for regulatory testing. Integr Environ Assess Manag 2010;6:301-307. © 2009 SETAC [ABSTRACT FROM AUTHOR]

The article offers information on assessment of endocrine disruption effects in vertebrates. Topics discussed include development of a regulation to identify the endocrine- disrupting properties of plant protection products (PPPs) by European Commission; hazard-based risks associated with plants involves restriction of safe products; and impact of PPPs on vertebrates physiology.