Multi-year field studies evaluating the benefits of vegetative filter strips
ACS 2019, AGRO 134
San Diego, California
Session Title: Off-Target Transport of Field Applied Agricultural Chemicals: Study Designs, Monitoring, Modelling, & Risk Assessment
Monday, August 26, 2019
1:55 pm, Ballroom 20B-D, Theater 5
Off-target agricultural chemical transport to surface water has been studied under USEPA Good Laboratory Practice Standards for many years to support environmental risk assessment. Field-scale runoff studies provide real-world data to understand the potential environmental exposure, resulting from runoff or erosion of agricultural chemicals. A multi-year field scale runoff study was designed to evaluate vegetative filter strip (VFS) performance under natural rainfall conditions in Missouri, under a corn/soybean crop rotation. The study consists of nine runoff plots with varying, replicated VFSs widths (3 plots each of: 0ft, 15ft, and 30ft). Additionally, plots were instrumented to facilitate future modeling. The runoff collection programming was designed with adherence to NRCS Edge-of-Field Monitoring System Guidance. Design complexities including unattended, refrigerated, runoff sample collection for a multi-year study under natural rainfall conditions will be discussed, and initial data collected from the treatments will be presented.
A. Ritter, F. Abi-Akar, P. Paulausky, G. Goodwin, J. Trask, L. Carver, M. Cox (Waterborne), A. Moore, C. Truman (Syngenta). Multi-year field studies evaluating the benefits of vegetative filter strips. Presentation, ACS 2019. AGRO 134. San Diego, California.
How ecosystem services credit exchanges allow private companies and public agencies an opportunity to comply with environmental laws, regulations, policies, and guidelines with a cost-effective, environmentally superior outcome
ACS 2019, AGRO 59
San Diego, California
Session Title: Pest Management Economics: Present & Future Considerations
Sunday, August 25, 2019
2:20 pm, Ballroom 20B-D, Theater 4
Using a system of ecosystem service credits and debits allows for exchanges of new conservation activities to zero out the anticipated negative ecological impacts of human activities on the landscape. In some circumstances, ecosystem offsets are designed to result in an overall biodiversity gain. Offsetting is generally considered the final stage in a mitigation hierarchy, whereby predicted impacts must first be demonstrated to maximize avoidance, then minimize unavoidable impacts before any remaining impacts are offset. The mitigation hierarchy is a step-down approach designed to deliver on the environmental policy principle of “No Net Loss.” Endangered species and habitat offset solutions developed to meet United States regulatory requirements and facilitate the effective permitting of ecological impacts have been in place for decades. This method of exchanging ecosystem credits for like debits can benefit the Environmental Protection Agency’s Endangered Species Act Section 7 pesticide consultations with the USFWS and NMFS. The consultation process is simplified when the proposed impacts are evaluated in concert with proposed high quality, assured offsets of a similar type and duration. This presentation will provide an overview of current habitat offset solutions and how private investment implements restoration and preservation projects that allow private companies and public agencies an opportunity to comply with environmental laws, regulations, policies and guidelines with a cost-effective, environmentally superior outcome. Highlights of the presentation include an overview of current ecosystem market offset solutions available and how these current private market mechanisms can provide solutions for both voluntary and regulated actions facing the crop protection industry. Real world examples from significant projects in California will be highlighted in the presentation.
B. Monaghan (Wildlands), J. Bickel (Waterborne). How ecosystem services credit exchanges allow private companies and public agencies an opportunity to comply with environmental laws, regulations, policies and guidelines with a cost-effective, environmentally superior outcome. Presentation, ACS 2019. AGRO 59. San Diego, California.
Biphasic sorption and transformation are key factors in the environmental fate of the herbicide monosodium methylarsenate
ACS 2019, AGRO 27
San Diego, California
Session Title: Creative Thinking in Designing Efate Studies & Data Analysis to Meet Agrochemical Regulatory Challenges
Sunday, August 25, 2019
11:35 am, Ballroom 20B-D, Theater 4
Monosodium methylarsenate (MSMA) is a selective contact herbicide used for post-emergent control of a very broad spectrum of weeds. In water, MSMA dissociates to monomethylarsonic acid (MMA) and sodium ions (Na+), and it can be metabolized by certain types of soil-dwelling microorganisms to form dimethylarsinic acid (DMA) through methylation, or inorganic arsenate through demethylation. The rate of metabolism decreases with time as a result of increased binding with soil minerals in a biphasic process. Its soil binding potential is proportional to the amorphous iron content of the soil and, to a lesser extent, soil pH – – more specifically, the extent of dissociation (a function of the pKa) – – and clay content. A recent soil column study, combined with a comprehensive analysis of an extensive database of published literature, have provided insight into quantifying and predicting the mechanisms, factors, and sorption kinetics. The sorption chemodynamics of MMA are highly relevant to determine the partitioning of the chemicals into the aqueous phase. The results of the analysis of the biphasic behavior, in the context of multi-factor environmental chemistry, will be presented. This work serves to resolve several of the questions regarding the environmental fate of MSMA.
S. Cohen (Environmental & Turf Services, Inc.), M. Williams (Waterborne), M. Eldan (Luxembourg-Pamol, Inc.), Y. Masue-Slowey (Exponent), P. Miner (Frontage Lab), J.M. Cheplick (Waterborne), and C. Hoogeweg (Waterborne). Biphasic sorption and transformation are key factors in the environmental fate of the herbicide monosodium methylarsenate. Presentation, ACS 2019. AGRO 27. San Diego, California.
Waterborne Nutrients Presentation
Outcomes from an ECETOC task force on geospatial approaches to increasing the ecological relevance of chemical risk assessments
SETAC Europe 2019, Poster
Session Title: 4D-Risk Assessment
Monday, May 27, 2019
5:15 pm, Exhibition Hall
For several decades, the prospective risk assessment of chemicals has followed a generic approach of comparing estimated exposures to toxic thresholds designed to be protective of all species (i.e., assessing exposure to the most sensitive species assumed to be located anywhere the chemical may occur in the environment). This approach does not recognise geographic patterns of species distributions or acknowledge that particularly sensitive species may not occupy potentially exposed habitats. Therefore, risk assessments could be overly conservative and restrictive for some uses of chemicals. Approaches for making spatially explicit assessments of chemical exposure are relatively advanced but this is not the case for mapping and assessing ecological data. However, geo-referenced ecological data appear to be increasingly available at spatial resolutions applicable to chemical risk assessment, potentially facilitating enhanced environmental relevance of such risk assessments. In 2017 a Task Force was initiated by European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC) to assess the capability of making chemical risk assessments using available geospatially referenced chemical exposure, ecological receptor and ecosystem services data. Two case studies were developed to illustrate the potential to assess geo-referenced risks to ecological receptors in fresh water and terrestrial environments exposed to i) a chemical used in consumer cleaning products discharged via municipal WWTPs across the EU and ii) a range of representative active ingredients used in plant protection products on selected crops in Germany. After initially compiling a catalogue of available geo-referenced ecological data for Europe, geo-referenced exposure concentrations were derived by combining accessible chemical use and fate data with conventional exposure models. However, use of many ecological data sets over a pan-European range proved problematic due to data access issues, limited geographic coverage and unreliable quality. Nevertheless, several suitable ecological data sets were accessed after making specific requests to various organisations within national authorities and these were integrated with the exposure maps. The results of these case studies give an indication of the potential value of making geo-referenced chemical risk assessments as well as the limitations to current capability.
S. Marshall (Consultant), A. Ireland (ExxonMobil Biomedical Sciences), J.C. Otte (BASF), L. Maltby (presenter; University of Sheffield), C. Holmes (Waterborne Environmental), and P. Sweeney (Syngenta). Outcomes from an ECETOC task force on geospatial approaches to increasing the ecological relevance of chemical risk assessments. Poster SETAC Europe 2019. Helsinki, Finland.
Applying the mechanistic honey bee colony model BEEHAVE to assess multiple factors impacting overwintering survival in large colony feeding studies
SETAC Europe 2019, Poster
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.
Modelling emissions of microplastics in Europe from wastewater sources, including land applied biosolids
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
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.
A prospective approach for assessing chemical mixtures in river catchments with diverse land uses
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
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