Ecological Models For Regulatory Risk Assessments Of Pesticides

Bringing together more than thirty influential regulators, academics, and industry scientists, Ecological Models for Regulatory Risk Assessments of Pesticides: Developing a Strategy for the Future provides a coherent, science-based view on ecological modeling for regulatory risk assessments. It discusses the benefits of modeling in the context of registrations, identifies the obstacles that prevent ecological modeling being used routinely in regulatory submissions, and explores the actions needed to overcome these obstacles. The book focuses on the following issues: Uncertainties in the process of model development, such as design, analysis, documentation, and communication The availability of data and background information needed for optimal modeling The limited knowledge of modeling The lack of confidence in the outcome of ecological models and their reliability in pesticide risk assessment It also suggests future solutions to these challenges, including: A guidance document on the modeling process Case studies that show how ecological models can provide reliable ecologically relevant risk assessments Training the people who generate or evaluate results obtained by ecological models Focusing on ecological models, such as unstructured population models, stage-structured matrix models, and individual- or agent-based models, this volume helps regulatory authorities, manufacturers, and scientists assess the risk of plant protection products in nontarget organisms. Armed with this knowledge, readers will better understand the challenges of using ecological modeling in the regulatory process.

Based on discussions at the 2007 SETAC Europe PERAS Workshop in Coimbra, Semi-Field Methods for the Environmental Risk Assessment of Pesticides in Soil presents a timely summary of state-of-the-art higher-tier terrestrial risk assessment of plant protection products (PPPs). Influential regulators, academics, and industry scientists provide a compre

While current methods used in ecological risk assessments for pesticides are largely deterministic, probabilistic methods that aim to quantify variability and uncertainty in exposure and effects are attracting growing interest from industries and governments. Probabilistic methods offer more realistic and meaningful estimates of risk and hence, pot

Pollinators play a vital role in ecosystem health and are essential to ensuring food security. With declines in both managed and wild pollinator populations in recent years, scientists and regulators have sought answers to this problem and have explored implementing steps to protect pollinator populations now and for the future. Pesticide Risk Assessment for Pollinators focuses on the role pesticides play in impacting bee populations and looks to develop a risk assessment process, along with the data to inform that process, to better assess the potential risks that can accompany the use of pesticide products. Pesticide Risk Assessment for Pollinators opens with two chapters that provide a biological background of both Apis and non-Apis species of pollinators. Chapters then present an overview of the general regulatory risk assessment process and decision-making processes. The book then discusses the core elements of a risk assessment, including exposure estimation, laboratory testing, and field testing. The book concludes with chapters on statistical and modeling tools, and proposed additional research that may be useful in developing the ability to assess the impacts of pesticide use on pollinator populations. Summarizing the current state of the science surrounding risk assessment for Apis and non-Apis species, Pesticide Risk Assessment for Pollinators is a timely work that will be of great use to the environmental science and agricultural research communities. Assesses pesticide risk to native and managed pollinators Summarizes the state of the science in toxicity testing and risk assessment Provides valuable biological overviews of both Apis and non-Apis pollinators Develops a plausible overall risk assessment framework for regulatory decision making Looks towards a globally harmonized approach for pollinator toxicity and risk assessment

The US Fish and Wildlife Service (FWS) and the National Marine Fisheries Service (NMFS) are responsible for protecting species that are listed as endangered or threatened under the Endangered Species Act (ESA) and for protecting habitats that are critical for their survival. The US Environmental Protection Agency (EPA) is responsible for registering or reregistering pesticides under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and must ensure that pesticide use does not cause any unreasonable adverse effects on the environment, which is interpreted to include listed species and their critical habitats. The agencies have developed their own approaches to evaluating environmental risk, and their approaches differ because their legal mandates, responsibilities, institutional cultures, and expertise differ. Over the years, the agencies have tried to resolve their differences but have been unsuccessful in reaching a consensus regarding their assessment approaches. As a result, FWS, NMFS, EPA, and the US Department of Agriculture asked the National Research Council (NRC) to examine scientific and technical issues related to determining risks posed to listed species by pesticides. Specifically, the NRC was asked to evaluate methods for identifying the best scientific data available; to evaluate approaches for developing modeling assumptions; to identify authoritative geospatial information that might be used in risk assessments; to review approaches for characterizing sublethal, indirect, and cumulative effects; to assess the scientific information available for estimating effects of mixtures and inert ingredients; and to consider the use of uncertainty factors to account for gaps in data. Assessing Risks to Endangered and Threatened Species from Pesticides, which was prepared by the NRC Committee on Ecological Risk Assessment under FIFRA and ESA, is the response to that request.

Mathematical models are being increasingly used to estimate the concentrations of a wide range of substances in the environment for a variety of reasons, including government control and legislation, and risk and hazard estimation. Exposure assessment has to be performed for many types of substances, including pesticides, industrial chemicals, pollutants, accidental discharges, etc. The interpretation of the results of model equations should always bear in mind the purpose for which the model used was built in the first place. Further, models are always an abstraction of reality, requiring simplifying assumptions to keep the models within the restraints posed by computer performance and/or scientific knowledge. The present book treats the theme of modelling chemical exposure and risk in terms of four main topics: model characteristics, applications, comparison of estimated with measured concentrations, and modelling credibility.

Global pesticide use is currently estimated at approximately 2. 5 billion kg per year (Pimentel eta/. , 1998). To be effective, pesticides need to persist for a certain period of time. However, the longer their persistence, the greater the potential for transport of a fraction of the amount applied away from the target area. Pesticides are dispersed in the environment by water currents, wind, or biota. Pesticides can directly contaminate ground and surface waters by leaching, surface run-off and drift. Pesticides can also enter the atmosphere during application by evaporation and drift of small spray droplets, that remain airborne. Following application, pesticides may volatilise from the crop or the soil. Finally, wind erosion can cause soil particles and dust loaded with pesticides to enter the atmosphere. The extent to which pesticides enter the air compartment is dependent upon many factors: the properties of the substance in question (e. g. vapour pressure), the amount used, the method of application, the formulation, the weather conditions (such as wind speed, temperature, humidity), the nature of the crop and soil characteristics. Measurements at application sites reveal that sometimes more than half of the amount applied is lost into the atmosphere within a few days (Spencer and Cliath, 1990; Taylor and Spencer; 1990; Van den Berg et a/. , this issue).

Expanding the risk assessment toolbox, this book provides a comprehensive and practical evaluation of specific ecological models for potential use in risk assessment. Ecological Modeling in Risk Assessment: Chemical Effects on Populations, Ecosystems, and Landscapes goes beyond current risk assessment practices for toxic chemicals as applied to individual-organism endpoints to describe ecological effects models useful at the population, ecosystem, and landscape levels. The authors demonstrate the utility of a set of ecological effects models, eventually improving the ecological relevance of risk assessments and making data collection more cost effective.