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PostersCrop Protection2019

Applying the mechanistic honey bee colony model BEEHAVE to assess multiple factors impacting overwintering survival in large colony feeding studies

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SETAC Europe 2019, Poster
Helsinki, Finland
Session Title: Bees, bugs and beneficials in environmental risk assessment and testing
Tuesday, May 28, 2019
8:30 am, Exhibition Hall

Honey bee Large Colony Feeding Study (LCFS) is a novel type of Tier II semi-field study for the determination of potential effects of pesticides on free-foraging whole colonies during and after dietary intake of a known pesticide concentration. LCFS are currently accepted by North American regulatory agencies and represent a progressively more realistic level of refinement compared to individual laboratory-based studies. LCFS are designed to test toxicity via consumption of fed sucrose syrup over a worst case exposure scenario of six weeks, with colony assessments conditions over a foraging season and following overwintering period. However, such studies are very cost- and time-intensive, and high overwintering losses of control hives have been observed in some studies. Loss of control colonies indicates that stressors other than pesticides, e.g. resource availability, weather, diseases and beekeeping activities, likely influence colony overwintering survival, confounding the assessment of impacts caused by pesticides. In the current study commissioned by the Pollinator Research Task Force, we apply the mechanistic honey bee colony model BEEHAVE to simulate colony dynamics observed in negative control colonies from multiple colony feeding studies. Detailed landscape-level data inform the resource availability for the simulated foragers in the model. In addition, weather data, initial colony condition and feeding patterns were analyzed across studies and translated to model inputs. In a calibration step, we adjusted parameters in BEEHAVE to achieve simulated dynamics corresponding to colony conditions reported in the studies. Study data collected in summer and fall were analyzed for predictors of overwintering success of individual colonies. BEEHAVE simulations with different combinations of external factors were used to assess their importance for colony condition. Colony conditions at study initialization and feeding patterns both influenced the colony condition in the fall, and thus, the probability of overwintering survival. Model simulations with different colony feeding patterns and initial colony conditions were then used to quantitatively estimate colony-level outcomes under conditions deviating from those in the studies. These results can be used to improve and inform LCFS study designs. Pesticide effects can be included in future model analyses, and analyzed in the context of multiple factors that impact colony health and overwintering success.

Amelie Schmolke (Waterborne Environmental), Farah Abi-Akar (Waterborne Environmental), Nika Galic (Syngenta), Silvia Hinarejos (presenter; Sumitomo Chemical Co.). Applying the mechanistic honey bee colony model BEEHAVE to assess multiple factors impacting overwintering survival in large colony feeding studies. Poster SETAC Europe 2019. Helsinki, Finland.

PostersWater/Wastewater Assessments2019

Modelling emissions of microplastics in Europe from wastewater sources, including land applied biosolids

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Public information regarding microplastics in the environment is frequently available and comes from a variety of sources, often in the form of retrospective sources such as measured aquatic data. Science-based risk assessment must utilize both retrospective and prospective exposure information to effectively estimate potential risk to ecological receptors. While monitoring data provide information at only a few locations for several points in time, prospective models can estimate the potential for ecological exposures across many landscapes and over long periods of time, and both have a role in risk assessment. Wastewater treatment plants are often cited as a source of microplastics entering the environment. Microplastics are highly removed (generally >90%) during the waste water treatment process, via skimming of floating particles or sorption to solids and settling into sludge. Understanding the eventual fate of this sludge, and the potential for contained microplastics to re-enter surface water, is one step of many in determining the fate of microplastics in the aquatic environment. Sludge management in Europe varies geographically, with up to 90% of sludge used on agriculture in Portugal, and 0% in other countries (Eurostat, 2017) with other disposal including incineration, landfill or composting. We present a model which addresses both direct aquatic emissions into surface water via waste water effluent, as well as indirectly from land applied biosolids coupled with spatially-defined surface runoff potential. Generalized runoff potential is estimated using fate and transport models used for plant protection products found in the EFSA FOCUS scenarios. To our knowledge, this coupling of direct aquatic emission and sludge-biosolids-runoff is a novel approach for examining environmental emissions of microplastics which enter municipal wastewater treatment plants. This spatially-explicit model is based on publicly available datasets, combined with a hydrologic framework containing geographically variable emissions linked to a river network simulating environmental transport via surface water.

Christopher Holmes, Joshua Amos, Amy Ritter, Marty Williams, and Scott Dyer (Waterborne Environmental). Modelling emissions of microplastics in Europe from wastewater sources, including land applied biosolids. Poster SETAC Europe 2019. Helsinki, Finland.

PresentationsHome and Personal Care Products2019

Using eco-epidemiology to assess the potential risks of UV filters to corals

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A recent study in Archives of Environmental Contamination and Toxicology (Downs et al 2016) indicating potential ecotoxicity issues for coral exposed to UV filters, such as benzophenone-3, has gained a global-level of visibility. This single study has provided laboratory evidence that calls into question the sufficiency of environmental risk assessments associated with benzophenone-3 via sunscreen use, particularly for swimmers and sunbathers. For sub-tropical and tropical climates, the potential occurrence for exposure of BP-3 may be year-around. Spatial coincidence of BP-3 exposure and marine ecosystems highly dependent on corals amplifies the potential issues highlighted in the Downs et al study. However, coral reefs have been shown to be adversely affected by numerous other chemical, biological and physical stressors, ranging from local to global scales. Hence, the protection of corals requires a multi-faceted approach that considers not only potential chemicals stressors, but physical stress – including temperature and changes in habitat quality. We advocate the use of eco-epidemiology to evaluate the relationships between environmental stressors and ecological status within a realistic ecological context. This approach supports the recognition that ecosystem status is driven by a multitude of physical, chemical and other environmental factors. Since the foundation of the evaluation relies on measured ecological status, recommendations from such an assessment have great potential for decision-making (including regulations) that will yield fruitful management actions. Our initial analysis utilizes data obtained from experts at the University of Hawaii (e.g., Coral Reef Assessment and Monitoring Program (CRAMP) http://cramp.wcc.hawaii.edu/default.htm). Measured UV filter and surrogate exposure data were collected for the island of Oahu from Mitchelmore et al (2018). To date, published works by the CRAMP experts indicate that both natural and anthropogenic factors may influence coral cover and species richness. Importantly, no single factor has been found to serve as a proxy for coral cover. Hence, it is clear that coral cover and species richness is dependent upon many factors. Based on CRAMP data alone, there appears to be a lack of data supporting the hypothesis that UV filters provide an adverse influence on corals. Our study places into context UV filters amongst several physical and chemical factors that potentially affect coral community health.

Scott Dyer (Waterborne Environmental), Christopher Holmes (Waterborne Environmental), Iain Davies (Personal Care Products Council), and Carys Mitchelmore (UMCES Chesapeake Biological Laboratory). Using eco-epidemiology to assess the potential risks of UV filters to corals.
Platform Presentation SETAC Europe 2019. Helsinki, Finland.

PostersWater/Wastewater Assessments2019

A prospective approach for assessing chemical mixtures in river catchments with diverse land uses

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Field-based ecological risk assessments incorporate risks from chemical mixtures and a myriad of stressors because ecosystems are continuously exposed to a wide-array of contaminants and nonchemical stressors. Considering the large numbers potential combinations of mixtures and stressors, this problem could seem insurmountable. We demonstrate that such combinations can be simplified by 3 land-use related chemical emission scenarios: agriculture, domestic, and urban. We applied a tiered methodology to assess the implications of each of the scenarios via a quantitative model. The results showed land use–dependent mixture exposures, clearly discriminating downstream effects of land uses, with unique chemical “signatures” regarding composition, concentration, and temporal patterns. Associated risks were characterized in relation to the land-use scenarios. Comparisons to measured environmental concentrations and predicted impacts showed relatively good similarity. The results suggest that the land uses imply exceedances of regulatory protective environmental quality standards, varying over time in relation to rain events and associated flow and dilution variation. Higher-tier analyses using ecotoxicological effect criteria confirmed that species assemblages may be affected by exposures exceeding no-effect levels and that mixture exposure could be associated with predicted species loss under certain situations. The model outcomes inform various types of prioritization to support risk management, including a ranking across land uses as a whole, a ranking on characteristics of exposure times and frequencies, and various rankings of the relative role of individual chemicals. Though all results are based on in silico assessments, our land use–based approach yields useful insights for simplifying and assessing potential ecological risks of chemical mixtures and can therefore be useful for catchment-management decisions.

Scott Dyer (Waterborne Environmental), Leo Posthuma (RIVM), Colin D. Brown (University of York), Dick de Zwart (RIVM), Jerome Diamond (Tetra Tech), Christopher Holmes (Waterborne Environmental), Stuart Marshall (Bedford, UK), and G. Allen Burton Jr (University of Michigan). A prospective approach for assessing chemical mixtures in river catchments with diverse land uses.
Poster SETAC Europe 2019. Helsinki, Finland.

Papers & ReportsAgriculture and Food, Crop Protection2018

Honey bee colony-level exposure and effects in realistic landscapes: An application of BEEHAVE simulating clothianidin residues in corn pollen

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Discerning potential effects of insecticides on honey bee colonies in field studies conducted under realistic conditions can be challenging because of concurrent interactions with other environmental conditions. Honey bee colony models can control exposures and other environmental factors, as well as assess links among pollen and nectar residues in the landscape, their influx into the colony, and the resulting exposures and effects on bees at different developmental stages. We extended the colony model BEEHAVE to represent exposure to the insecticide clothianidin via residues in pollen from treated cornfields set in real agricultural landscapes in the US Midwest. We assessed their potential risks to honey bee colonies over a 1-yr cycle. Clothianidin effects on colony strength were only observed if unrealistically high residue levels in the pollen were simulated. The landscape composition significantly impacted the collection of pollen (residue exposure) from the cornfields, resulting in higher colony-level effects in landscapes with lower proportions of semi-natural land. The application of the extended BEEHAVE model with a pollen exposure-effects module provides a case study for the application of a mechanistic honey bee colony model in pesticide risk assessment integrating the impact of a range of landscape compositions.

Schmolke, A., Abi-Akar, F., Hinarejos, S. (2018), Honey bee colony-level exposure and effects in realistic landscapes: An application of BEEHAVE simulating clothianidin residues in corn pollen. Environ Toxicol Chem. DOI: 10.1002/etc.4314

Papers & ReportsCrop Protection2018

A plea for consistency, transparency, and reproducibility in risk assessment effect models

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Ecological risk assessments (ERAs) are moving toward using populations and ecosystem services as explicit protection goals, and impacts on these are difficult, if not impossible, to measure empirically. Mechanistic effect models are recognized as necessary tools for ERA that complement empirical data. But we need a strategy to make them consistent, transparent and reproducible following similar principles as those used to develop standardized experimental designs for empirical tests. Despite some progress, the use of mechanistic effect models in ERA remains rare. Although some general guidance exists, the ERA community lacks a coherent strategy for model design and implementation. The strategy needs to be compatible with different legislative needs, recognize limitations in data and resources, and involve all stakeholder groups to ensure buy-in. Benefits would include increased cost-effectiveness of model development, implementation and interpretation; minimization of effort needed by risk assessors and managers to evaluate models; and more effective communication of model outputs to a broader stakeholder community. More importantly, it would increase mechanistic understanding of the impacts of chemicals and other stressors across levels of biological organization – from the things that we measure to the things that we care about.

Forbes, V.E., Schmolke, A., Accolla, C., Grimm, V. (2018), A plea for consistency, transparency, and reproducibility in risk assessment effect models. Environ Toxicol Chem. 38: 9-11. doi.org/10.1002/etc.4291

Papers & ReportsCrop Protection2018

Plant guttation water as a potential route for pesticide exposure in honey bees: a review of recent literature

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Because honey bees periodically collect water, guttation water from treated crops has been suggested as a potential exposure route to systemic pesticides. We reviewed studies that were published in the scientific literature since a previous review of the topic. We identified several studies that reported residue levels of pesticides in guttation water. However, few studies addressed guttation water as a potential exposure route to honey bees. In these studies, no significant effects on honey bee colony health or overwintering survival were observed when colonies were located within fields of treated crops during guttation periods. The previous and current review suggests that exposure to pesticides via guttation water alone is unlikely to negatively affect honey bee colonies. A better understanding of water foraging by honey bees would be needed to address whether guttation water could represent a relevant exposure route of honey bees to systemic pesticides.

Schmolke, A., Kearns, B., O’Neil, B. (2018), Plant guttation water as a potential route for pesticide exposure in honey bees: a review of recent literature. Apidologie. Volume 49, 637-646. doi.org/10.1007/s13592-018-0591-1

Papers & ReportsWater/Wastewater Assessments2018

Simplifying environmental mixtures-An aquatic exposure-based approach via land use scenarios

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Posthuma, L., Brown, C., de Zwart, D., Diamond, J., Dyer, S.D., Hamer, M., Holmes, C.M., Marshal, S., Burton Jr., G.A. (2018), Simplifying environmental mixtures-an aquatic exposure-based approach via land use scenarios. Environ Toxicol Chem. 37: 671-673. doi.org/10.1002/etc.4063

Papers & ReportsCrop Protection2018

Adapting population models for application in pesticide risk assessment: a case study with Mead’s milkweed

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Population models can facilitate assessment of potential impacts of pesticides on populations or species rather than individuals and have been identified as important tools for pesticide risk assessment of nontarget species including those listed under the Endangered Species Act. Few examples of population models developed for this specific purpose are available; however, population models are commonly used in conservation science as a tool to project the viability of populations and the long‐term outcomes of management actions. We present a population model for Mead’s milkweed (Asclepias meadii), a species listed as threatened under the Endangered Species Act throughout its range across the Midwestern United States. We adapted a published population model based on demographic field data for application in pesticide risk assessment. Exposure and effects were modeled as reductions of sets of vital rates in the transition matrices, simulating both lethal and sublethal effects of herbicides. Two herbicides, atrazine and mesotrione, were used as case study examples to evaluate a range of assumptions about potential exposure-effects relationships. In addition, we assessed buffers (i.e., setback distances of herbicide spray applications from the simulated habitat) as hypothetical mitigation scenarios and evaluated their influence on population‐level effects in the model. The model results suggest that buffers can be effective at reducing risk from herbicide drift to plant populations. These case studies demonstrate that existing population models can be adopted and integrated with exposure and effects information for use in pesticide risk assessment.

Schmolke, A., Roy, C., Brain, R., Forbes, V. (2018), Adapting population models for application in pesticide risk assessment: A case study with Mead’s milkweed. Environ Toxicol Chem. 37: 2235-2245. doi.org/10.1002/etc.4172

Papers & ReportsWater/Wastewater Assessments2017

Prospective aquatic risk assessment for chemical mixtures in agricultural landscapes

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Environmental risk assessment of chemical mixtures is challenging because of the multitude of possible combinations that may occur. Aquatic risk from chemical mixtures in an agricultural landscape was evaluated prospectively in 2 exposure scenario case studies: at field scale for a program of 13 plant‐protection products applied annually for 20 yr and at a watershed scale for a mixed land‐use scenario over 30 yr with 12 plant‐protection products and 2 veterinary pharmaceuticals used for beef cattle. Risk quotients were calculated from regulatory exposure models with typical real‐world use patterns and regulatory acceptable concentrations for individual chemicals. The results could differentiate situations when there was concern associated with single chemicals from those when concern was associated with a mixture (based on concentration addition) with no single chemical triggering concern. Potential mixture risk was identified on 0.02 to 7.07% of the total days modeled, depending on the scenario, the taxa, and whether considering acute or chronic risk. Taxa at risk were influenced by receiving water body characteristics along with chemical use profiles and associated properties. The present study demonstrates that a scenario‐based approach can be used to determine whether mixtures of chemicals pose risks over and above any identified using existing approaches for single chemicals, how often and to what magnitude, and ultimately which mixtures (and dominant chemicals) cause greatest concern.

Holmes, C.M., Brown, C.D., Hamer, M., Jones, R., Maltby, L., Posthuma, L., Silberhorn, E., Teeter, J.S., St J Warne, M., Weltje, L. (2017), Prospective aquatic risk assessment for chemical mixtures in agricultural landscapes. Environ Toxicol Chem. 37: 674-689. doi.org/10.1002/etc.4049