Towards a landscape scale management of pesticides: ERA using changes in modelled occupancy and abundance to assess long-term population impacts of pesticides

Effects of plant protection products on ecosystem functions provided by terrestrial invertebrates

Plant protection products (PPP) are extensively used to protect plants against harmful organisms, but they also have unintended effects on non-target organisms, especially terrestrial invertebrates. The impact of PPP on ecosystem functions provided by these non-target invertebrates remains, however, unclear. The objectives of this article were to review PPP impacts on the ecosystem functions provided by pollinators, predators and parasitoids, and soil organisms, and to identify the factors that aggravate or mitigate PPP effects. The literature highlights that PPP alter several ecosystem functions: provision and maintenance of biodiversity, pollination, biotic interactions and habitat completeness in terrestrial ecosystems, and organic matter and soil structure dynamics. However, there are still a few studies dealing with ecosystem functions, with sometimes contradictory results, and consequences on agricultural provisioning services remain unclear. The model organisms used to assess PPP ecotoxicological effects are still limited, and should be expanded to better cover the wide functional diversity of terrestrial invertebrates. Data are lacking on PPP sublethal, transgenerational, and "cocktail" effects, and on their multitrophic consequences. In empirical assessments, studies on PPP unintended effects should consider agricultural-pedoclimatic contexts because they influence the responses of non-target organisms and associated ecosystem functions to PPP. Modeling might be a promising way to account for the complex interactions among PPP mixtures, biodiversity, and ecosystem functioning.

Pesticide Exposure and Effects on Non-Apis Bees

Bees are essential pollinators of many crops and wild plants, and pesticide exposure is one of the key environmental stressors affecting their health in anthropogenically modified landscapes. Until recently, almost all information on routes and impacts of pesticide exposure came from honey bees, at least partially because they were the only model species required for environmental risk assessments (ERAs) for insect pollinators. Recently, there has been a surge in research activity focusing on pesticide exposure and effects for non-Apis bees, including other social bees (bumble bees and stingless bees) and solitary bees. These taxa vary substantially from honey bees and one another in several important ecological traits, including spatial and temporal activity patterns, foraging and nesting requirements, and degree of sociality. In this article, we review the current evidence base about pesticide exposure pathways and the consequences of exposure for non-Apis bees. We find that the insights into non-Apis bee pesticide exposure and resulting impacts across biological organizations, landscapes, mixtures, and multiple stressors are still in their infancy. The good news is that there are many promising approaches that could be used to advance our understanding, with priority given to informing exposure pathways, extrapolating effects, and determining how well our current insights (limited to very few species and mostly neonicotinoid insecticides under unrealistic conditions) can be generalized to the diversity of species and lifestyles in the global bee community. We conclude that future research to expand our knowledge would also be beneficial for ERAs and wider policy decisions concerning pollinator conservation and pesticide regulation.

Aquatic Risks at the Landscape Scale: A Case Study for Pyrethroid Use in Pome Fruit Orchards in Belgium

Procedures for environmental risk assessment for pesticides are under continuous development and subject to debate, especially at higher tier levels. Spatiotemporal dynamics of both pesticide exposure and effects at the landscape scale are largely ignored, which is a major flaw of the current risk assessment system. Furthermore, concrete guidance on risk assessment at landscape scales in the regulatory context is lacking. In this regard, we present an integrated modular simulation model system that includes spatiotemporally explicit simulation of pesticide application, fate, and effects on aquatic organisms. As a case study, the landscape model was applied to the Rummen, a river catchment in Belgium with a high density of pome fruit orchards. The application of a pyrethroid to pome fruit and the corresponding drift deposition on surface water and fate dynamics were simulated. Risk to aquatic organisms was quantified using a toxicokinetic/toxicodynamic model for individual survival at different levels of spatial aggregation, ranging from the catchment scale to individual stream segments. Although the derivation of landscape-scale risk assessment end points from model outputs is straightforward, a dialogue within the community, building on concrete examples as provided by this case study, is urgently needed in order to decide on the appropriate end points and on the definition of representative landscape scenarios for use in risk assessment.

Is the effectiveness of policy-driven mitigation measures on carabid populations driven by landscape and farmland heterogeneity? Applying a modelling approach in the Dutch agroecosystems

The growing challenges of protecting biodiversity in agro-ecosystems and maintaining high agricultural productivity has become an important issue within the European Union, shaping both European and national agro-policies. The presented study is part of a broader evaluation of the interim targets of the 2013 Dutch policy plan on sustainable use of pesticides, carried out in 2019 by the PBL (Planbureau voor de Leefomgeving) Netherlands Environmental Assessment Agency. We aimed to assess the effectiveness of selected mitigation measures suggested in the policy plan on non-target terrestrial arthropods using a common carabid beetle Bembidion lampros as a model species. We combined dynamic landscape models with detailed agent-based population modelling to simulate impacts of reduction of toxicity of insecticides, reduction of spray drift to the off-crop area, and increase in area of field margins on the beetle population dynamics in ten agricultural landscapes representing different farming systems. Our simulations showed that a shift towards low-risk products should be the priority if the goal is to increase beetle range. To promote local beetle abundance this needs be coupled with increasing amount of field margins in a landscape. Overall, the observed treatment and landscape effects were highly context-specific and therefore we suggest that care is used when defining and interpretting metrics based on population effects of policy measures. This caveat notwithstanding, the use of simulation to assess complex interactions between landscape, ecology and behaviour of species, and policy measures can be a powerful tool supporting innovative policy management. This should include the development of landscape-context specific targets and/or mitigation measures.

Heterogeneity in biological assemblages and exposure in chemical risk assessment: Exploring capabilities and challenges in methodology with two landscape-scale case studies

Chemical exposure concentrations and the composition of ecological receptors (e.g., species) vary in space and time, resulting in landscape-scale (e.g. catchment) heterogeneity. Current regulatory, prospective chemical risk assessment frameworks do not directly address this heterogeneity because they assume that reasonably worst-case chemical exposure concentrations co-occur (spatially and temporally) with biological species that are the most sensitive to the chemical's toxicity. Whilst current approaches may parameterise fate models with site-specific data and aim to be protective, a more precise understanding of when and where chemical exposure and species sensitivity co-occur enables risk assessments to be better tailored and applied mitigation more efficient. We use two aquatic case studies covering different spatial and temporal resolution to explore how geo-referenced data and spatial tools might be used to account for landscape heterogeneity of chemical exposure and ecological assemblages in prospective risk assessment. Each case study followed a stepwise approach: i) estimate and establish spatial chemical exposure distributions using local environmental information and environmental fate models; ii) derive toxicity thresholds for different taxonomic groups and determine geo-referenced distributions of exposure-toxicity ratios (i.e., potential risk); iii) overlay risk data with the ecological status of biomonitoring sites to determine if relationships exist. We focus on demonstrating whether the integration of relevant data and potential approaches is feasible rather than making comprehensive and refined risk assessments of specific chemicals. The case studies indicate that geo-referenced predicted environmental concentration estimations can be achieved with available data, models and tools but establishing the distribution of species assemblages is reliant on the availability of a few sources of biomonitoring data and tools. Linking large sets of geo-referenced exposure and biomonitoring data is feasible but assessment of risk will often be limited by the availability of ecotoxicity data. The studies highlight the important influence that choices for aggregating data and for the selection of statistical metrics have on assessing and interpreting risk at different spatial scales and patterns of distribution within the landscape. Finally, we discuss approaches and development needs that could help to address environmental heterogeneity in chemical risk assessment.

The Animal Landscape and Man Simulation System (ALMaSS): a history, design, and philosophy

This article is the first article in the new topical RIO journal collection for ALMaSS. This editorial introduces ALMaSS, its history, component parts and philosophy, and forms a first access point for those interested in knowing more. It is written from my own personal perspective as the instigator and main developer for the system, effectively as the ‘father’ of ALMaSS.

A critical review of effect modeling for ecological risk assessment of plant protection products

A wide diversity of plant protection products (PPP) is used for crop protection leading to the contamination of soil, water, and air, which can have ecotoxicological impacts on living organisms. It is inconceivable to study the effects of each compound on each species from each compartment, experimental studies being time consuming and cost prohibitive, and animal testing having to be avoided. Therefore, numerous models are developed to assess PPP ecotoxicological effects. Our objective was to provide an overview of the modeling approaches enabling the assessment of PPP effects (including biopesticides) on the biota. Six categories of models were inventoried: (Q)SAR, DR and TKTD, population, multi-species, landscape, and mixture models. They were developed for various species (terrestrial and aquatic vertebrates and invertebrates, primary producers, micro-organisms) belonging to diverse environmental compartments, to address different goals (e.g., species sensitivity or PPP bioaccumulation assessment, ecosystem services protection). Among them, mechanistic models are increasingly recognized by EFSA for PPP regulatory risk assessment but, to date, remain not considered in notified guidance documents. The strengths and limits of the reviewed models are discussed together with improvement avenues (multigenerational effects, multiple biotic and abiotic stressors). This review also underlines a lack of model testing by means of field data and of sensitivity and uncertainty analyses. Accurate and robust modeling of PPP effects and other stressors on living organisms, from their application in the field to their functional consequences on the ecosystems at different scales of time and space, would help going toward a more sustainable management of the environment. Graphical Abstract Combination of the keyword lists composing the first bibliographic query. Columns were joined together with the logical operator AND. All keyword lists are available in Supplementary Information at https://doi.org/10.5281/zenodo.5775038 (Larras et al. 2021).

The Role of Source-Sink Dynamics in the Assessment of Risk to Nontarget Arthropods from the Use of Plant Protection Products

The concept of source-sink dynamics as a potentially important component of metapopulation dynamics was introduced in the 1980s. The objective of the present review was to review the considerable body of work that has been developed, to consider its theoretical implications as well as to understand how source-sink dynamics may manifest under field conditions in the specific case of nontarget arthropods in the agricultural environment. Our review concludes that metapopulation dynamics based on field observations are often far more complex than existing theoretical source-sink models would indicate, because they are dependent on numerous population processes and influencing factors. The difficulty in identifying and measuring these factors likely explains why empirical studies assessing source-sink dynamics are scarce. Furthermore, we highlight the importance of considering the spatial and temporal heterogeneity of agricultural landscapes when assessing the population dynamics of nontarget arthropods in the context of the risk from the use of plant protection products. A need is identified to further develop and thoroughly validate predictive population models, which can incorporate all factors relevant to a specific system. Once reliable predictive models for a number of representative nontarget arthropod species are available, they could provide a meaningful tool for refined risk evaluations (higher tier level risk assessment), addressing specific concerns identified at the initial evaluation stages (lower tier level risk assessment). Environ Toxicol Chem 2021;40:2667-2679. © 2021 ERM, FMC, Syngenta, Bayer AG, BASF SE, Corteva agriscience. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Pesticide use in sugar beet cultivation in Germany and assessment of the associated environmental risks using the risk indicator SYNOPS-GIS

BACKGROUND

The assessment of the environmental risks for pesticides is a current topic of the European Union (EU) strategy 'Farm to Fork'. Therefore, an analysis of the status quo of pesticide use from 2010 to 2015 and the associated environmental risks was performed for sugar beet cultivation in Germany. Based on this assessment, crop protection strategies should be developed that contribute to risk reduction.

RESULTS

Pesticide use data from 2314 randomly chosen sugar beet growing farms were available from annual farm surveys from 2010 until 2015. Possible environmental risks from pesticide applications were calculated with the model SYNOPS-GIS. Each pesticide application pattern was combined with several model fields. The concentrations of active ingredients in the non-target compartments, namely soil, neighboring surface waters and field margins, were used to determined risk indices (exposure toxicity ratios, ETRs) for different terrestrial and aquatic reference species. ETRs were mainly lower than a risk threshold used throughout this study (ETR = 1). The risks caused by herbicide use were studied in more detail since herbicides are applied on nearly all fields. The aquatic risks posed by herbicides were independent of specific active ingredients or application patterns. Instead, certain combinations of active ingredients, application dates and field-specific environmental conditions provoked higher risks. The aquatic risks were strongly influenced by the distance of the fields to surface waters.

CONCLUSIONS

Further risk mitigation seems possible by combining field-specific measures and technical options. © 2021 Society of Chemical Industry.

Conservation risks and benefits of establishing monarch butterfly (Danaus plexippus) breeding habitats close to maize and soybean fields in the north central United States: A landscape-scale analysis of the impact of foliar insecticide on nonmigratory monarch butterfly populations

Establishing habitat in agricultural landscapes of the north central United States is critical to reversing the decline of North America's eastern monarch butterfly (Danaus plexippus) population. Insecticide use could create population sinks and threaten recovery. Discouraging habitat establishment within a 38-m zone around crop fields is a suggested risk mitigation measure. In Story County, Iowa, United States, this mitigation would discourage habitat establishment in 84% of roadsides and 38% of noncrop land. It is unclear if the conservation benefits from establishing habitat close to crop fields outweigh suppression of population growth owing to insecticide exposure. Consequently, monarch conservation plans require spatially and temporally explicit landscape-scale assessments. Using an agent-based model that incorporates female monarch movement and egg laying, the number and location of eggs laid in Story County were simulated for four habitat scenarios: current condition, maximum new establishment, moderate establishment, and moderate establishment only outside a 38-m no-plant zone around crop fields. A demographic model incorporated mortality from natural causes and insecticide exposure to simulate adult monarch production over 10 years. Assuming no insecticide exposure, simulated adult production increased 24.7% and 9.3%, respectively, with maximum and moderate habitat establishment and no planting restrictions. A 3.5% increase was simulated assuming moderate habitat establishment with a 38-m planting restriction. Impacts on adult production were simulated for six representative insecticides registered for soybean aphid (Aphis glycines) management. Depending on the frequency of insecticide applications over a 10-year period, simulated production increased 8.2%-9.3%, assuming moderate habitat establishment with no planting restrictions. Results suggest that the benefits of establishing habitat close to crop fields outweigh the adverse effects of insecticide spray drift; that is, metapopulation extirpation is not a concern for monarchs. These findings are only applicable to species that move at spatial scales greater than the scale of potential spray-drift impacts. Integr Environ Assess Manag 2021;17:989-1002. © 2021 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Supporting non-target arthropods in agroecosystems: Modelling effects of insecticides and landscape structure on carabids in agricultural landscapes

Intensification of agricultural practices is one of the most important drivers of the dramatic decline of arthropod species. We do not know, however, the relative contribution to decline of different anthropogenic stressors that are part of this process. We used high-resolution dynamic landscape models and advanced spatially-explicit population modelling to estimate the relative importance of insecticide use and landscape structure for population dynamics of a widespread carabid beetle Bembidion lampros. The effects of in-crop mitigation measures through the application of insecticides with reduced lethality, and off-crop mitigation measures by increasing abundance of grassy field margins, were evaluated for the beetle along the gradient of landscape heterogeneity. Reducing the insecticide-driven lethality (from 90 to 10%) had larger positive impacts on beetle density and occupancy than increasing the abundance of field margins in a landscape. The effects of increasing field margins depended on their width and overall abundance in the landscape, but only field margins 4 m wide, applied to at least 40% of fields, resulted in an increase in beetle population density comparable to the scenario with the smallest reduction of insecticide-driven lethality we considered. Our findings suggest the importance of field margins rather as a supporting not stand-alone mitigation measure, as they generally improved effects of reduction of insecticide-driven lethality. Therefore, adding sufficiently broad off-field habitats should help to maintain viable beetle populations in agricultural landscapes even with moderate use of insecticides. In general, the less persistent the insecticides are in the environment, the larger positive impacts of applied mitigation measures on beetle populations were found. We also showed that the effectiveness of applied mitigation measures strongly depends on landscape and farmland heterogeneity. Thus, to achieve the same management or mitigation target in different landscapes might require different strategies.

A systems-based approach to the environmental risk assessment of multiple stressors in honey bees

The European Parliament requested EFSA to develop a holistic risk assessment of multiple stressors in honey bees. To this end, a systems-based approach that is composed of two core components: a monitoring system and a modelling system are put forward with honey bees taken as a showcase. Key developments in the current scientific opinion (including systematic data collection from sentinel beehives and an agent-based simulation) have the potential to substantially contribute to future development of environmental risk assessments of multiple stressors at larger spatial and temporal scales. For the monitoring, sentinel hives would be placed across representative climatic zones and landscapes in the EU and connected to a platform for data storage and analysis. Data on bee health status, chemical residues and the immediate or broader landscape around the hives would be collected in a harmonised and standardised manner, and would be used to inform stakeholders, and the modelling system, ApisRAM, which simulates as accurately as possible a honey bee colony. ApisRAM would be calibrated and continuously updated with incoming monitoring data and emerging scientific knowledge from research. It will be a supportive tool for beekeeping, farming, research, risk assessment and risk management, and it will benefit the wider society. A societal outlook on the proposed approach is included and this was conducted with targeted social science research with 64 beekeepers from eight EU Member States and with members of the EU Bee Partnership. Gaps and opportunities are identified to further implement the approach. Conclusions and recommendations are made on a way forward, both for the application of the approach and its use in a broader context.

Statement of the PPR Panel on a framework for conducting the environmental exposure and risk assessment for transition metals when used as active substances in plant protection products (PPP)

The European Commission asked the European Food Safety Authority (EFSA) to prepare a statement on a framework for the environmental risk assessment (ERA) of transition metals (e.g. iron and copper) used as active substances in plant protection products (PPPs). Non-degradability, essentiality and specific conditions affecting fate and behaviour as well as their toxicity are distinctive characteristics possibly not covered in current guidance for PPPs. The proposed risk assessment framework starts with a preliminary phase, in which monitoring data on transition metals in relevant environmental compartments are provided. They deliver the metal natural background and anthropogenic residue levels to be considered in the exposure calculations. A first assessment step is then performed assuming fully bioavailable residues. Should the first step fail, refined ERA can, in principle, consider bioavailability issues; however, non-equilibrium conditions need to be taken into account. Simple models that are fit for purpose should be employed in order to avoid unnecessary complexity. Exposure models and scenarios would need to be adapted to address environmental processes and parameters relevant to the fate and behaviour of transition metals in water, sediment and soils (e.g. speciation). All developments should follow current EFSA guidance documents. If refined approaches have been used in the risk assessment of PPPs containing metals, post-registration monitoring and controlled long-term studies should be conducted and assessed. Utilisation of the same transition metal in other PPPs or for other uses will lead to accumulation in environmental compartments acting as sinks. In general, it has to be considered that the prospective risk assessment of metal-containing PPPs can only cover a defined period as there are limitations in the long-term hazard assessment due to issues of non-degradability. It is therefore recommended to consider these aspects in any risk management decisions and to align the ERA with the goals of other overarching legislative frameworks.

Effect of plant protection on assemblages of ground beetles (Coleoptera, Carabidae) in sugar beet crops in four-year rotation

The influence of chemical plant protection on carabid beetle assemblages was studied in an experiment conducted on fields of sugar beet at the IOR-PIB Experimental Station in Winna Góra, Poland. The experiment was composed of a block of control fields (no chemical plant protection treatments) and second block, where plant protection was carried out in compliance with the applicable plant protection program. Ground beetles were caught from May to August/September in four years, using modified Barber traps. As a result of the study, 11 881 specimens belonging to 52 species of Carabidae were collected. The most numerous species were: Harpalus rufipes, Pterostichus melanarius, Calathus ambiguus and Bembidion properans. Overall, our results demonstrate that the application of chemical plant protection treatments decreased the abundance of carabid beetles in sugar beet fields, but had no effect on species richness. The use of pesticides induced changes in some life traits of Carabidae fauna. After a pesticide application, the abundance of macropterous hemizoophages and medium carnivores with the autumn type of breeding decreased, whereas the abundance of small carnivores increased.

European hares do not avoid newly pesticide-sprayed fields: Overspray as unnoticed pathway of pesticide exposure

Although risk assessments for pesticides involve quantifying exposure routes for animals, little empirical evidence exists on how individuals use areas where pesticides were used. Further, the European Food Safety Authority guidelines for the risk assessment of birds and mammals currently only include direct dietary uptake from exposed plants as important pathway for pesticides, arguing that dermal exposure is generally negligible. Here, we use the European hare (Lepus europaeus) as a model of a farmland specialist to investigate if (1) hares adjust habitat use in response to pesticide spraying, using GPS data, and (2) calculate the pesticide exposure and uptake over different pathways, i.e. foraging uptake versus overspray and subsequent oral grooming, using an agent-based modelling approach. Apart from avoidance of sprayed fields on the spraying day by inactive hares, which was likely caused by the mechanical disturbance rather than the pesticide itself, we found no evidence that hares reduced the use of pesticide-sprayed fields compared to control observations where no pesticides were applied. Our simulation showed that both the proportion of exposed individuals and the pesticide uptake were related to the pathway of exposure (foraging versus overspray/oral grooming), and depended on the age class and the vegetation type. We found that pesticide uptake via overspray/oral grooming might be 7-fold higher compared to foraging and might thus be an important pathway of pesticide exposure in hares. Our findings emphasize that policy makers, specifically the European Food Safety Authority, should incorporate alternative pathways of pesticide exposure for birds and mammals, such as overspray and oral grooming, when conducting environmental risk assessments and take variation in vegetation structure and age-related animal behavior into account, because these factors might affect pesticide exposure. Interactions between pesticide application and vegetation structure may both increase or decrease exposure but can be predicted using a simulation approach.

Risk assessment for pesticide mixtures on aquatic ecosystems in China: a proposed framework

BACKGROUND

With over 12 000 registered mixture formulations in China, environmental risk assessment of co-formulated pesticide mixtures to aquatic ecosystems is of increasing interest to scientists, risk assessors, and risk managers. This study proposed a pragmatic approach based on widely accepted scientific concepts and strategies.

RESULTS

The proposed approach has three tiers, a preliminary Tier 0 stage, a Tier 1 stage, and a refinement stage as Tier 2, which are demonstrated with one case study. Because of the large number of co-formulated pesticide mixtures available in China, a unique Tier 0 stage is proposed with practicable criteria to identify mixtures requiring further evaluation. For Tier-1 assessment, exposure is assessed based on the application scheme and local scenarios in China. Hazard is evaluated using the concentration addition model as the default approach, which was developed a century ago and was adopted by the majority of the regulators globally. Given the unique characteristics of mixtures in the environment, data variability and ratio changes of active ingredients are also evaluated for hazard assessment. More accurate assessments with decreased uncertainties can be achieved by higher tier refinements in Tier-2, such as alternative models, consideration of co-formulants, and higher tier effect and exposure analyses.

CONCLUSION

Widely accepted concepts, methodologies, and criteria should be used for aquatic risk assessment for pesticide mixtures in China. To avoid unnecessary workload and a more accurate assessment, unique perspectives such as local agricultural practice, local scenarios and a preliminary screening stage (Tier 0) should be implemented. © 2019 Society of Chemical Industry.

The Impact of Pesticides on Flower-Visiting Insects: A Review with Regard to European Risk Assessment

Flower-visiting insects (FVIs) are an ecologically diverse group of mobile, flying species that should be protected from pesticide effects according to European policy. However, there is an ongoing decline of FVI species, partly caused by agricultural pesticide applications. Therefore, the risk assessment framework needs to be improved. We synthesized the peer-reviewed literature on FVI groups and their ecology, habitat, exposure to pesticides, and subsequent effects. The results show that FVIs are far more diverse than previously thought. Their habitat, the entire agricultural landscape, is potentially contaminated with pesticides through multiple pathways. Pesticide exposure of FVIs at environmentally realistic levels can cause population-relevant adverse effects. This knowledge was used to critically evaluate the European regulatory framework of exposure and effect assessment. The current risk assessment should be amended to incorporate specific ecological properties of FVIs, that is, traits. We present data-driven tools to improve future risk assessments by making use of trait information. There are major knowledge gaps concerning the general investigation of groups other than bees, the collection of comprehensive data on FVI groups and their ecology, linking habitat to FVI exposure, and study of previously neglected complex population effects. This is necessary to improve our understanding of FVIs and facilitate the development of a more protective FVI risk assessment. Environ Toxicol Chem 2019;38:2355-2370. © 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.

Overcoming Challenges of Incorporating Higher Tier Data in Ecological Risk Assessments and Risk Management of Pesticides in the United States: Findings and Recommendations from the 2017 Workshop on Regulation and Innovation in Agriculture

Pesticide regulation requires regulatory authorities to assess the potential ecological risk of pesticides submitted for registration, and most risk assessment schemes use a tiered testing and assessment approach. Standardized ecotoxicity tests, environmental fate studies, and exposure models are used at lower tiers and follow well-defined methods for assessing risk. If a lower tier assessment indicates that the pesticide may pose an ecological risk, higher tier studies using more environmentally realistic conditions or assumptions can be performed to refine the risk assessment and inform risk management options. However, there is limited guidance in the United States on options to refine an assessment and how the data will be incorporated into the risk assessment and risk management processes. To overcome challenges to incorporation of higher tier data into ecological risk assessments and risk management of pesticides, a workshop was held in Raleigh, North Carolina. Attendees included representatives from the United States Environmental Protection Agency, United States Department of Agriculture, National Oceanic and Atmospheric Administration, universities, commodity groups, consultants, nonprofit organizations, and the crop protection industry. Key recommendations emphasized the need for 1) more effective, timely, open communication among registrants, risk assessors, and risk managers earlier in the registration process to identify specific protection goals, address areas of potential concern where higher tier studies or assessments may be required, and if a higher tier study is necessary that there is agreement on study design; 2) minimizing the complexity of study designs while retaining high value to the risk assessment and risk management process; 3) greater transparency regarding critical factors utilized in risk management decisions with clearly defined protection goals that are operational; and 4) retrospective analyses of success-failure learnings on the acceptability of higher tier studies to help inform registrants on how to improve the application of such studies to risk assessments and the risk management process. Integr Environ Assess Manag 2019;15:714-725. © 2019 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Using problem formulation for fit-for-purpose pre-market environmental risk assessments of regulated stressors

Pre-market/prospective environmental risk assessments (ERAs) contribute to risk analyses performed to facilitate decisions about the market introduction of regulated stressors. Robust ERAs begin with an explicit problem formulation, which involves among other steps: (1) formally devising plausible pathways to harm that describe how the deployment of a regulated stressor could be harmful; (2) formulating risk hypotheses about the likelihood and severity of such events; (3) identifying the information that will be useful to test the risk hypotheses; and (4) developing a plan to acquire new data for hypothesis testing should tests with existing information be insufficient for decision-making. Here, we apply problem formulation to the assessment of possible adverse effects of RNA interference-based insecticidal genetically modified (GM) plants, GM growth hormone coho salmon, gene drive-modified mosquitoes and classical biological weed control agents on non-target organisms in a prospective manner, and of neonicotinoid insecticides on bees in a retrospective manner. In addition, specific considerations for the problem formulation for the ERA of nanomaterials and for landscape-scale population-level ERAs are given. We argue that applying problem formulation to ERA maximises the usefulness of ERA studies for decision-making, through an iterative process, because: (1) harm is defined explicitly from the start; (2) the construction of risk hypotheses is guided by policy rather than an exhaustive attempt to address any possible differences; (3) existing information is used effectively; (4) new data are collected with a clear purpose; (5) risk is characterised against well-defined criteria of hypothesis corroboration or falsification; and (6) risk assessment conclusions can be communicated clearly. However, problem formulation is still often hindered by the absence of clear policy goals and decision-making criteria (e.g. definition of protection goals and what constitutes harm) that are needed to guide the interpretation of scientific information. We therefore advocate further dialogue between risk assessors and risk managers to clarify how ERAs can address policy goals and decision-making criteria. Ideally, this dialogue should take place for all classes of regulated stressors, as this can promote alignment and consistency on the desired level of protection and maximum tolerable impacts across regulated stressors.

Predictive models in ecotoxicology: Bridging the gap between scientific progress and regulatory applicability-Remarks and research needs

This paper concludes a special series of 7 articles (4 on toxicokinetic-toxicodynamic [TK-TD] models and 3 on quantitative structure-activity relationship [QSAR] models) published in previous issues of Integrated Environmental Assessment and Management (IEAM). The present paper summarizes the special series articles and highlights their contribution to the topic of increasing the regulatory applicability of effect models. For both TK-TD and QSAR approaches, we then describe the main research needs. The use of TK-TD models for describing sublethal effects must be better developed, particularly through the improvement of the dynamic energy budget (DEBtox) approach. The potential of TK-TD models for moving from lower (molecular) to higher (population) hierarchical levels is highlighted as a promising research line. Some relevant issues to improve the acceptance of QSAR models at the regulatory level are also described, such as increased transparency of the performance assessment and of the modeling algorithms, model documentation, relevance of the chosen target for regulatory needs, and improved mechanistic interpretability. Integr Environ Assess Manag 2019;00:000-000. © 2019 SETAC.

A Spatio-Temporal Exposure-Hazard Model for Assessing Biological Risk and Impact

We developed a simulation model for quantifying the spatio-temporal distribution of contaminants (e.g., xenobiotics) and assessing the risk of exposed populations at the landscape level. The model is a spatio-temporal exposure-hazard model based on (i) tools of stochastic geometry (marked polygon and point processes) for structuring the landscape and describing the exposed individuals, (ii) a dispersal kernel describing the dissemination of contaminants from polygon sources, and (iii) an (eco)toxicological equation describing the toxicokinetics and dynamics of contaminants in affected individuals. The model was implemented in the briskaR package (biological risk assessment with R) of the R software. This article presents the model background, the use of the package in an illustrative example, namely, the effect of genetically modified maize pollen on nontarget Lepidoptera, and typical comparisons of landscape configurations that can be carried out with our model (different configurations lead to different mortality rates in the treated example). In real case studies, parameters and parametric functions encountered in the model will have to be precisely specified to obtain realistic measures of risk and impact and accurate comparisons of landscape configurations. Our modeling framework could be applied to study other risks related to agriculture, for instance, pathogen spread in crops or livestock, and could be adapted to cope with other hazards such as toxic emissions from industrial areas having health effects on surrounding populations. Moreover, the R package has the potential to help risk managers in running quantitative risk assessments and testing management strategies.

RECOTOX, a French initiative in ecotoxicology-toxicology to monitor, understand and mitigate the ecotoxicological impacts of pollutants in socioagroecosystems

RECOTOX is a cross-cutting initiative promoting an integrated research to respond to the challenges of monitoring, understanding, and mitigating environmental and health impacts of pesticides in agroecosystems. The added value of RECOTOX is to develop a common culture around spatial ecotoxicology including the whole chain of pressure-exposure-impact, while strengthening an integrated network of in natura specifically equipped sites. In particular, it promotes transversal approaches at relevant socioecological system scales, to capitalize knowledge, expertise, and ongoing research in ecotoxicology and, to a lesser extent, environmental toxicology. Thus, it will open existing research infrastructures in environmental sciences to research programs in ecotoxicology of pesticides.

Current EU research activities on combined exposure to multiple chemicals

Humans and wildlife are exposed to an intractably large number of different combinations of chemicals via food, water, air, consumer products, and other media and sources. This raises concerns about their impact on public and environmental health. The risk assessment of chemicals for regulatory purposes mainly relies on the assessment of individual chemicals. If exposure to multiple chemicals is considered in a legislative framework, it is usually limited to chemicals falling within this framework and co-exposure to chemicals that are covered by a different regulatory framework is often neglected. Methodologies and guidance for assessing risks from combined exposure to multiple chemicals have been developed for different regulatory sectors, however, a harmonised, consistent approach for performing mixture risk assessments and management across different regulatory sectors is lacking. At the time of this publication, several EU research projects are running, funded by the current European Research and Innovation Programme Horizon 2020 or the Seventh Framework Programme. They aim at addressing knowledge gaps and developing methodologies to better assess chemical mixtures, by generating and making available internal and external exposure data, developing models for exposure assessment, developing tools for in silico and in vitro effect assessment to be applied in a tiered framework and for grouping of chemicals, as well as developing joint epidemiological-toxicological approaches for mixture risk assessment and for prioritising mixtures of concern. The projects EDC-MixRisk, EuroMix, EUToxRisk, HBM4EU and SOLUTIONS have started an exchange between the consortia, European Commission Services and EU Agencies, in order to identify where new methodologies have become available and where remaining gaps need to be further addressed. This paper maps how the different projects contribute to the data needs and assessment methodologies and identifies remaining challenges to be further addressed for the assessment of chemical mixtures.

Linking pesticide marketing authorisations with environmental impact assessments through realistic landscape risk assessment paradigms

Each year, the European Food Safety Authority, supported by a network of experts in the EU Member States, assesses and publishes the environmental risks of 30-40 pesticides active substances. The assessments support hundreds of national risk evaluations for marketing (re-)authorisations of Plant Protection Products. These prospective regulatory evaluations are based on worst-case scenarios in order to provide the high level of protection required by the EU legislations, and establishes the conditions for a correct use of the products including risk mitigations options. However, recent publications suggest that the desired high level of protection may not be achieved with the current risk assessment paradigm. The consideration of larger spatial scales and multiple stressors, including different pesticide uses, could improve the risk assessment process. A next step is the use of these larger spatial scales for evidence-based assessments, evaluating the overall impact of pesticide use on the European environment and biodiversity. Reaching this level would provide science-based support to the National Plans on sustainable use of pesticides and to the broader EU policies defined in the EU Environmental Action Programmes. Recent technological developments, as well as policy efforts, have solved two of the key issues blocking this progress in the past. Data availability and technical capacity for handling Big Data are no longer an unaffordable obstacle. The current proposal presents an alternative environmental risk assessment paradigm, integrating use patterns and pesticides properties with landscape ecotypes and eco-regions, covering the variability of the European agro-environmental conditions. The paradigm is suggested to be implemented in a spatially explicit conceptual model, using the ecosystem services approach and vulnerable key driver species to represent the service providing units. This approach would allow mapping the likelihood and magnitude of the impact of pesticide use on ecosystems functions, environmental resources, and biodiversity at the EU scale.

Spatial exposure-hazard and landscape models for assessing the impact of GM crops on non-target organisms

The cultivation of Genetically Modified (GM) crops may have substantial impacts on populations of non-target organisms (NTOs) in agroecosystems. These impacts should be assessed at larger spatial scales than the cultivated field, and, as landscape-scale experiments are difficult, if not impossible, modelling approaches are needed to address landscape risk management. We present an original stochastic and spatially explicit modelling framework for assessing the risk at the landscape level. We use techniques from spatial statistics for simulating simplified landscapes made up of (aggregated or non-aggregated) GM fields, neutral fields and NTO's habitat areas. The dispersal of toxic pollen grains is obtained by convolving the emission of GM plants and validated dispersal kernel functions while the locations of exposed individuals are drawn from a point process. By taking into account the adherence of the ambient pollen on plants, the loss of pollen due to climatic events, and, an experimentally-validated mortality-dose function we predict risk maps and provide a distribution giving how the risk varies within exposed individuals in the landscape. Then, we consider the impact of the Bt maize on Inachis io in worst-case scenarii where exposed individuals are located in the vicinity of GM fields and pollen shedding overlaps with larval emergence. We perform a Global Sensitivity Analysis (GSA) to explore numerically how our input parameters influence the risk. Our results confirm the important effects of pollen emission and loss. Most interestingly they highlight that the optimal spatial distribution of GM fields that mitigates the risk depends on our knowledge of the habitats of NTOs, and finally, moderate the influence of the dispersal kernel function.

Advantages and challenges associated with implementing an ecosystem services approach to ecological risk assessment for chemicals

The ecosystem services (ES) approach is gaining broad interest in regulatory and policy arenas for use in landscape management and ecological risk assessment. It has the potential to bring greater ecological relevance to the setting of environmental protection goals and to the assessment of the ecological risk posed by chemicals. A workshop, organised under the auspices of the Society of Environmental Toxicology and Chemistry Europe, brought together scientific experts from European regulatory authorities, the chemical industry and academia to discuss and evaluate the challenges associated with implementing an ES approach to chemical ecological risk assessment (ERA). Clear advantages of using an ES approach in prospective and retrospective ERA were identified, including: making ERA spatially explicit and of relevance to management decisions (i.e. indicating what ES to protect and where); improving transparency in communicating risks and trade-offs; integrating across multiple stressors, scales, habitats and policies. A number of challenges were also identified including: the potential for increased complexity in assessments; greater data requirements; limitations in linking endpoints derived from current ecotoxicity tests to impacts on ES. In principle, the approach was applicable to all chemical sectors, but the scale of the challenge of applying an ES approach to general chemicals with widespread and dispersive uses leading to broad environmental exposure, was highlighted. There was agreement that ES-based risk assessment should be based on the magnitude of impact rather than on toxicity thresholds. The need for more bioassays/tests with functional endpoints was recognized, as was the role of modelling and the need for ecological production functions to link measurement endpoints to assessment endpoints. Finally, the value of developing environmental scenarios that can be combined with spatial information on exposure, ES delivery and service provider vulnerability was recognized.

Scientific Opinion on the state of the science on pesticide risk assessment for amphibians and reptiles

Following a request from EFSA, the Panel on Plant Protection Products and their Residues developed an opinion on the science to support the potential development of a risk assessment scheme of plant protection products for amphibians and reptiles. The coverage of the risk to amphibians and reptiles by current risk assessments for other vertebrate groups was investigated. Available test methods and exposure models were reviewed with regard to their applicability to amphibians and reptiles. Proposals were made for specific protection goals aiming to protect important ecosystem services and taking into consideration the regulatory framework and existing protection goals for other vertebrates. Uncertainties, knowledge gaps and research needs were highlighted.

Ecological risk assessment of agricultural soils for the definition of soil screening values: A comparison between substance-based and matrix-based approaches

The Italian legislation on contaminated soils does not include the Ecological Risk Assessment (ERA) and this deficiency has important consequences for the sustainable management of agricultural soils. The present research compares the results of two ERA procedures applied to agriculture (i) one based on the "substance-based" approach and (ii) a second based on the "matrix-based" approach. In the former the soil screening values (SVs) for individual substances were derived according to institutional foreign guidelines. In the latter, the SVs characterizing the whole-matrix were derived originally by the authors by means of experimental activity. The results indicate that the "matrix-based" approach can be efficiently implemented in the Italian legislation for the ERA of agricultural soils. This method, if compared to the institutionalized "substance based" approach is (i) comparable in economic terms and in testing time, (ii) is site specific and assesses the real effect of the investigated soil on a battery of bioassays, (iii) accounts for phenomena that may radically modify the exposure of the organisms to the totality of contaminants and (iv) can be considered sufficiently conservative.

Environmental risk assessment of pesticides: state of the art and prospective improvement from science

Pesticide risk assessment in the European regulatory framework is mandatory performed for active substances (pesticides) and the plant protection products they are constituents of. The aim is to guarantee that safe use can be achieved for the intended use of the product. This paper provides a feedback on the regulatory environmental risk assessment performed for pesticide registration at the EU and member state levels. The different steps of pesticide registration are addressed considering both exposure and hazard. In this paper, we focus on the environmental fate and behaviour in surface water together with the aquatic ecotoxicity of the substances to illustrate pesticide regulatory risk assessment performed for aquatic organisms. Current methodologies are presented along with highlights on potential improvements. For instance, as regards exposure aspects, moving from field based to landscape risk assessments is promising. Regarding ecotoxicology, ecological models may be valuable tools when applied to chemical risk assessment. In addition, interest and further developments to better take into account mitigation measures in risk assessment and management are also presented.

Scientific Opinion addressing the state of the science on risk assessment of plant protection products for in-soil organisms

Following a request from EFSA, the Panel on Plant Protection Products and their Residues developed an opinion on the science behind the risk assessment of plant protection products for in-soil organisms. The current risk assessment scheme is reviewed, taking into account new regulatory frameworks and scientific developments. Proposals are made for specific protection goals for in-soil organisms being key drivers for relevant ecosystem services in agricultural landscapes such as nutrient cycling, soil structure, pest control and biodiversity. Considering the time-scales and biological processes related to the dispersal of the majority of in-soil organisms compared to terrestrial non-target arthropods living above soil, the Panel proposes that in-soil environmental risk assessments are made at in- and off-field scale considering field boundary levels. A new testing strategy which takes into account the relevant exposure routes for in-soil organisms and the potential direct and indirect effects is proposed. In order to address species recovery and long-term impacts of PPPs, the use of population models is also proposed.

Exploration of Trends in Interspecific Abundance-Occupancy Relationships Using Empirically Derived Simulated Communities

The interspecific abundance-occupancy relationship (AOR) is a widely used tool that describes patterns of habitat utilization and, when evaluated over time, may be used to identify large-scale changes in community structure. Our primary goal for this research was to validate the utility of AORs as temporal indicators of community state. We used long-term survey data in four regions of the northwest Atlantic coastal shelf (NWACS) to estimate the diversity of spatial behaviors in each community, which we modeled with negative binomial (NB) distributions. NB parameters were used to generate time series data for simulated communities, from which AORs were then estimated and evaluated for temporal trends. We found that AORs from simulated communities were similar in year-to-year variation to empirical relationships. In order to further understand the role of spatial diversity in the generation of AOR trends, we did additional simulations where NB parameters were manually manipulated. In one instance, we ran simulations while holding species’ parameters constant over time. This treatment effectively removed trends, suggesting that temporal change in community relationships was the result of genuine variation in intraspecific spatial use. In another set of simulations, we conducted a case study to evaluate the impact of a select group of schooling and spatially aggregating species on an especially rapid shift in AORs in the Gulf of Maine from 1973 to 1983. Removals of these species reduced the magnitudes of most trends, demonstrating their importance to observed community changes. This research directly links variation in AORs to distribution and density-related processes and provides a potentially powerful framework to identify community-level change and to test ecological and mechanistic hypotheses.

The pros and cons of ecological risk assessment based on data from different levels of biological organization

Ecological risk assessment (ERA) is the process used to evaluate the safety of manufactured chemicals to the environment. Here we review the pros and cons of ERA across levels of biological organization, including suborganismal (e.g., biomarkers), individual, population, community, ecosystem and landscapes levels. Our review revealed that level of biological organization is often related negatively with ease at assessing cause-effect relationships, ease of high-throughput screening of large numbers of chemicals (it is especially easier for suborganismal endpoints), and uncertainty of the ERA because low levels of biological organization tend to have a large distance between their measurement (what is quantified) and assessment endpoints (what is to be protected). In contrast, level of biological organization is often related positively with sensitivity to important negative and positive feedbacks and context dependencies within biological systems, and ease at capturing recovery from adverse contaminant effects. Some endpoints did not show obvious trends across levels of biological organization, such as the use of vertebrate animals in chemical testing and ease at screening large numbers of species, and other factors lacked sufficient data across levels of biological organization, such as repeatability, variability, cost per study and cost per species of effects assessment, the latter of which might be a more defensible way to compare costs of ERAs than cost per study. To compensate for weaknesses of ERA at any particular level of biological organization, we also review mathematical modeling approaches commonly used to extrapolate effects across levels of organization. Finally, we provide recommendations for next generation ERA, submitting that if there is an ideal level of biological organization to conduct ERA, it will only emerge if ERA is approached simultaneously from the bottom of biological organization up as well as from the top down, all while employing mathematical modeling approaches where possible to enhance ERA. Because top-down ERA is unconventional, we also offer some suggestions for how it might be implemented efficaciously. We hope this review helps researchers in the field of ERA fill key information gaps and helps risk assessors identify the best levels of biological organization to conduct ERAs with differing goals.

Landscape structure and management alter the outcome of a pesticide ERA: Evaluating impacts of endocrine disruption using the ALMaSS European Brown Hare model

There is a gradual change towards explicitly considering landscapes in regulatory risk assessment. To realise the objective of developing representative scenarios for risk assessment it is necessary to know how detailed a landscape representation is needed to generate a realistic risk assessment, and indeed how to generate such landscapes. This paper evaluates the contribution of landscape and farming components to a model based risk assessment of a fictitious endocrine disruptor on hares. In addition, we present methods and code examples for generation of landscape structures and farming simulation from data collected primarily for EU agricultural subsidy support and GIS map data. Ten different Danish landscapes were generated and the ERA carried out for each landscape using two different assumed toxicities. The results showed negative impacts in all cases, but the extent and form in terms of impacts on abundance or occupancy differed greatly between landscapes. A meta-model was created, predicting impact from landscape and farming characteristics. Scenarios based on all combinations of farming and landscape for five landscapes representing extreme and middle impacts were created. The meta-models developed from the 10 real landscapes failed to predict impacts for these 25 scenarios. Landscape, farming, and the emergent density of hares all influenced the results of the risk assessment considerably. The study indicates that prediction of a reasonable worst case scenario is difficult from structural, farming or population metrics; rather the emergent properties generated from interactions between landscape, management and ecology are needed. Meta-modelling may also fail to predict impacts, even when restricting inputs to combinations of those used to create the model. Future ERA may therefore need to make use of multiple scenarios representing a wide range of conditions to avoid locally unacceptable risks. This approach could now be feasible Europe wide given the landscape generation methods presented.