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PresentationsCrop Protection2021

Screening-level pollinator risk assessment for trisiloxane polyether surfactants (Part II): Effects and risk characterization

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ACS 2021, AGRO Division, Zoom Room 03
Session Title: Screening-level pollinator risk assessment for trisiloxane polyether surfactants (Part II): Effects and risk characterization
Thursday, August 26, 2021, 05:25 pm – 05:50 pm USA/Canada – Eastern

The screening-level pollinator risk assessment for three trisiloxane polyether surfactants will expand on the exposure characterization presented in Part I. In this phase, the ecotoxicological effects of three trisiloxane polyether surfactants were evaluated and incorporated with the exposure characterization to evaluate risk. The US EPA model, BeeREX, was used to conduct a Tier I screening-level model assessment to generate risk quotients for comparison against levels of concern. The effects characterization included a review of endpoints from acute and chronic laboratory studies for both larval and adult stage honeybees (Apis mellifera) following published OECD test guidelines. Estimated residue concentrations calculated in Part I were compared to the relevant acute and chronic endpoints (acute 50% lethal dose, LD50 and chronic no-observed-effect dose, NOED) from several GLP toxicology studies to determine the risk quotients (RQs) for this assessment. This presentation will include a comparison of calculated RQs and to defined regulatory levels of concern for pollinator risk assessment, as well as a discussion of the uncertainty analysis.

 

J. Collins (Waterborne). Screening-level pollinator risk assessment for trisiloxane polyether surfactants (Part II): Effects and risk characterization. AGRO, ACS 2021. Virtual Meeting.

PresentationsCrop Protection2021

Screening-level pollinator risk assessment for trisiloxane polyether surfactants (Part I): Challenges and methodologies for estimating exposure of honeybees (Apis mellifera)

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ACS 2021, AGRO Division, Zoom Room 03
Session Title: Screening-level pollinator risk assessment for trisiloxane polyether surfactants (Part I): Challenges and methodologies for estimating exposure of honeybees (Apis mellifera)
Thursday, August 26, 2021, 05:00 pm – 05:25 pm USA/Canada – Eastern

The pollinator risk assessment framework laid out by US EPA, PRMA, and CDPR (2014) is primarily focused on pesticide active ingredients. In recent years, there has been increased interest in the potential impact, if any, to human health and the environment of inert ingredients (i.e., non-pesticidally active components of pesticide products) and chemical substances used as tank mix adjuvants and surfactants. Trisiloxane polyethers represent a class of superspreader surfactants with the unique ability of significantly reducing the surface tension of water to promote a rapid spreading of aqueous solutions on the surfaces of leaves. Since limited data is available regarding routes of exposure to honeybees from trisiloxanes, there are some challenges in the evaluation of exposure characterization. The objective of this presentation is to layout the challenges in the exposure characterization of three trisiloxane polyether surfactants and discuss various methodologies employed to conservatively quantify exposure for use in a screening-level pollinator risk assessment framework for these surfactants. The BeeREX Tier I screening-level risk assessment model uses maximum application rates to estimate worst-case exposure concentrations in various honeybee matrices via model default residue assumptions, for instances where available residue data are not available. The model also provides a refinement option using available residue data. The CDPR Pesticide Use Registry (PUR) database was used to determine reasonable maximum surfactant application rates, which were modeled to determine worst-case exposure rates using default residue assumptions. In addition, refined exposure estimates were determined by incorporating surfactant residues generated in a field residue study.

J. Collins (Waterborne), A. Schmolke (Waterborne)

Screening-level pollinator risk assessment for trisiloxane polyether surfactants (Part I): Challenges and methodologies for estimating exposure of honeybees (Apis mellifera) AGRO, ACS 2021

PresentationsAgriculture and Food, Crop Protection2021

Overview of the chemical degradation kinetics pathway tool and practical considerations for its application for model inputs

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ACS 2021, AGRO Division, Zoom Room 04
Session Title: Overview of the chemical degradation kinetics pathway tool and practical considerations for its application for model inputs
Monday, August 23, 2021, 10:35 am – 11:00 am USA/Canada – Eastern

Reliable chemical degradation tools for modeling kinetic pathways are imperative to conducting accurate human health and environmental risk assessments. While the EU FOCUS organization has extensive guidance for conducting the analysis and software tools have been developed in many iterations (CAKE, KinGUII, Model Maker, etc), the USEPA has not formally released tools or guidance for pathway modeling. In 2020, the USEPA included a kinetics software tool, Deg Kinetics v 2.8.2, for kinetic evaluation of chemical degradation data for applications in drinking water assessments with several evaluations. This Excel based solver serves as a useful tool for modeling single first order chemical pathways and evaluation of degradation within the pathway as an input into the typical exposure models used by USEPA, PMRA, and state agencies. This presentation will utilize the Deg Kinetics v 2.8.2 tool in the context of real-world application of the tool as a comparison of its setup, inputs, and parameter selection to that of other FOCUS typical kinetics tools. Finally, this presentation will provide an overview of methods for combining data from multiple datasets as inputs into the model framework – specifically regarding considerations with rapidly degrading parent to daughter and granddaughter compounds and the impact on model predictions.

P. Paulausky (Waterborne), A. Ritter (Waterborne), N. Snyder (Waterborne). Overview of the chemical degradation kinetics pathway tool and practical considerations for its application for model inputs. AGRO, ACS 2021, Virtual Meeting

PresentationsAgriculture and Food, Crop Protection2021

Collection of water monitoring data: Working in the spirit of GLPs

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ACS 2021, AGRO Division, Zoom Room 04
Session Title: Collection of water monitoring data: Working in the spirit of GLPs
Monday, August 23, 2021, 07:25 pm – 07:45 pm USA/Canada – Eastern

Over time the accessibility and processes used for the collection of water monitoring data has changed. The days of transcription from laboratory reports are becoming minimal and electronic data files from comprehensive databases are becoming more commonplace, which requires new approaches for data reproducibility and documentation. Over the past decade, water monitoring data have been collected under the “spirit of the GLPs” in its documentation, reproducibility, and archival. While all aspects of the GLP program are not required, critical steps throughout the data collection and processing follow the underlying principles of the GLPs. As more electronic data were collected from a variety of sources, the process of how to standardize these data increased in complexity. Challenges such as data transformation, traceability, and connections to historic data needed to be addressed to ensure data quality and to answer questions from regulators. In addition, we have continued to enhance our data processing protocols to ensure consistency in data handling, analysis, and documentation of uncertainty. For studies in which GLPs are not necessarily required by a sponsor, we explore an approach of operating under the “spirit of the GLPs” to ensure that monitoring data processes and summarization are repeatable, traceable and provide confidence around electronic data processing and archival similar to those electronic data collected under GLP programs.

J. Trask (Waterborne), L. Johnson (Waterborne), J. Crider (Waterborne)

Collection of water monitoring data: Working in the spirit of GLPs. AGRO, ACS 2021, Virtual Meeting

PresentationsAgriculture and Food, Crop Protection2021

Using GIS overlay methods to determine vulnerable agricultural areas in the Ukraine

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ACS 2021, AGRO Division, Zoom Room 02
Session Title: Using GIS overlay methods to determine vulnerable agricultural areas in the Ukraine
Monday, August 23, 2021, 05:50 pm – 06:15 pm USA/Canada – Eastern

GIS overlay methods such as vulnerability index methods are frequently used to assess the relative vulnerability of groundwater or surface water to contaminants. The application of these methods is driven in large part by data availability, and assessor expertise and familiarity. This may result in a bias in the models as certain criteria are over- or underemphasized; for example, pesticide behavior is often ignored in commonly used index methods, where environmental factors such as pH and organic carbon have been shown to affect the local vulnerability of groundwater and surface water. Furthermore, vulnerability index methods may feature subjective weights and rankings, which increases the likelihood of bias. Two new index methods using a standardized approach are introduced and applied to determine groundwater and surface water vulnerability for corn production areas in the Ukraine. For groundwater, the following parameters were included: average annual rainfall, topsoil sand content, topsoil organic carbon content, topsoil pH, drainage class and depth to groundwater. For surface water, key variables included slope, days with more than 25.4 mm of rainfall, topsoil available water capacity, topsoil organic carbon content, topsoil pH and drainage class. A weighting schema was developed for each of the variables. Weights ranged from 1 to 6, with 1 being the lowest weight and 6 being the highest weight and were based on six percentile classes. This has the advantage that the distribution of variables is accounted for and are unbiased, and that the method can be easily applied to other regions to provide a systematic and transparent assessment approach. Using this approach, the maximum vulnerability score is 36 and the results show the relative vulnerability for both groundwater and surface water. For groundwater, 12.7% of the total agricultural areas fall in the upper percentile class (>83.3%) of vulnerability and have scores 26 – 33. For surface water 13.2% of the total agricultural areas falling into the upper percentile class and have scores 26 – 35. The maximum attainable vulnerable score of 36 was not achieved in either assessment.

 

C. Hoogeweg (Waterborne), N. Peranginangin (Syngenta), R. Krueger (Waterborne), A. Ritter (Waterborne)

Using GIS overlay methods to determine vulnerable surface water areas in the Ukraine. AGRO, ACS 2021, Virtual Meeting

PresentationsAgriculture and Food, Crop Protection2021

Using GIS overlay methods to determine vulnerable surface water areas in Brazil

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ACS 2021, AGRO Division, Zoom Room 02
Session Title: Using GIS overlay methods to determine vulnerable surface water areas in Brazil
Monday, August 23, 2021 05:25 pm – 05:50 pm USA/Canada – Eastern

Brazil’s diverse agricultural landscape poses challenges to assess the impact of agricultural chemicals due to the differences in climate, unique soils, and agricultural management practices across the country. The aim of this project was to determine areas in Brazil that are currently under soybean production and potentially vulnerable to surface water runoff. Potential vulnerable areas were determined by conducting a GIS overlay of soils, climate, and topography data within likely soybean production areas. Potential vulnerable areas were defined as areas having soils with high levels of clay and rainfall with steep slopes, soils low in water holding capacity, and/or poor drainage. The results from this assessment can be used to select potential vulnerable areas for detailed exposure modeling using regulatory accepted environmental fate models. The municipalities with the highest soybean production are located in Mato Grosso (Central Brazil), Paraná, Santa Catarina and Rio Grande Do Sul in southern Brazil. The lowest runoff index was calculated to be 11 and the highest 35. Areas with lower runoff potential are found throughout Brazil and are more prevalent than high runoff potential areas. When the runoff index dataset is filtered to the soybean production areas, regions in Santa Catarina, Paraná and Goiás all have areas with a high (>27) runoff index. This indicates that compared to other soybean producing regions, these areas are more likely to be vulnerable to runoff. Only 9.24% of the soybean regions fall in the highest runoff vulnerability class, having an index of 27 or greater. The majority, 70.66%, of the areas fall within the median range of vulnerability (index 16 – 26). The frequency distribution chart of runoff vulnerability indices shows a bi-modal distribution. The theoretical highest vulnerability value of 42 was never reached in this assessment.

C. Hoogeweg (Waterborne), M. Urban (Syngenta), J. Schulze-Aurich (Syngenta), W. Phelps (Syngenta), A. Cione (Syngenta), A. Ritter (Waterborne). Using GIS overlay methods to determine vulnerable surface water areas in Brazil. AGRO, ACS 2021. Virtual Meeting

PostersAgriculture and Food, Crop Protection2021

A Novel Approach for Estimating Flow During Submerged Tile Conditions

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ASABE 2021 Annual Meeting, July 2021

Session:  Natural Resource and Environmental Systems (#23 Drainage Group)

Abstract: Accurate tile flow rate and flow volume estimates are critical to estimating subsurface nutrient runoff. Efforts have been made to improve the accuracy and ease of flow estimates during free flow conditions using water level control structures paired with weirs and water level instrumentation. However, in fields experiencing submerged tile conditions, few options exist for estimating tile flow beyond installing velocity-based flow instrumentation, which is often cost-prohibitive. This work proposes a method for estimating flow rate and volume during submerged tile conditions by taking into account flow proportion of monitored and unmonitored tile laterals based on field flow lines, assessing the proportion of tile main runoff attributed to each lateral using historical free-flowing event data, and applying the new lateral flow proportions in conjunction with weir equations to produce a modified flow calculation. This method is applied to a sample field research site with 45 total tile laterals (18 monitored, 27 unmonitored) using water level data for flow events between 2017-2020.

Authors:  Patricia Paulausky, Farah Abi-Akar, Russell Krueger (Waterborne Environmental), Laura Gentry (Illinois Corn Growers Association), Gregory Goodwin (Waterborne Environmental).  ASABE 2021 Annual International Meeting.

Problem Definition of a Harmonised Framework for Spatially Distributed Leaching Modelling (SDLM) of Pesticides

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Session:  Measuring, Monitoring and Modelling of Pesticide Fate and Mitigation in a Regulatory Context

Abstract:  Spatially distributed leaching modelling (SDLM) of pesticides is a methodology to estimate the leaching potential of plant protection products over an extensive spatial scale such as national or European. It is described as a higher tier in the current European Guidance for groundwater risk assessment. Whereas this option is an integral part of the tiered assessment scheme only little guidance is provided on how to conduct such spatial assessments with SDLM. Guidance on how to perform such leaching assessments is therefore needed, as well as version control for high-resolution spatial databases for the EU. It was therefore decided to establish a working group under the umbrella of the SETAC Environmental Monitoring Advisory Group on Pesticides (SETAC EMAG-PEST). This document describes the aim and scope of the work to be performed by this working group. The main products of the working group will be a harmonised modelling framework including the data needed to run these models, and documents describing the use of the framework in regulatory assessments. The framework will serve two different Tiers of the groundwater risk assessment scheme, i.e. Tier-3b and Tier-4. At Tier-3b, the framework will deliver the same exposure assessment goal as currently used in FOCUS groundwater, i.e. the 80th-spatial and temporal percentiles of the leaching concentration at 1-m depth. This exposure assessment goal is considered a conservative estimate of the real groundwater concentration. To ensure consistency of the tiered approach, the modelling framework will support all parameter refinements carried out at Tier-2. At Tier-4, the measured groundwater concentration in groundwater wells is assessed. The modelling framework plays a crucial role for the selection of vulnerable regions in which to install monitoring wells. It can also be used to demonstrate whether existing groundwater monitoring studies have been carried out at locations that are sufficiently vulnerable in view of the existing FOCUS exposure assessment goal. The modelling framework will, however, not simulate the actual concentration in the groundwater wells, because additional processes occur between 1 m depth and the position of the groundwater wells. The Working Group will consist of members from academia, regulators and industry. It will consist of a Steering Committee, a subgroup on spatial data and a subgroup on modelling. The Working Group will deliver two years after the start of the project.

Authors: Bernhard Jene (BASF), Aaldrik Tiktak (PBL), Abdul Ghafoor (KEMI), Anton Poot (CTGB), Erik van den Berg (Wageningen University), Cornelis Hoogeweg (Waterborne), Michael Klein (Fraunhofer IME), Michael Stemmer (AGES), Paul Sweeney (Syngenta), Robin Sur (Bayer AG)

PostersCrop Protection2021

Impact of Climate Change on the Relevance of OECD Crosswalks

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Session:  Extended submission 3 – Environmental chemistry and exposure assessment: analysis, monitoring, fate and modeling

Abstract:  Climate change studies confirm that the earth is warming up and that shifts in rainfall patterns is occurring. Various computer models predict that Earth’s average temperature will rise between 1.8° and 4.0° Celsius (3.2° and 7.2° F). Consequently, these warmer temperatures will cause a higher rate of evaporation, resulting in a predicted increase of average global rainfall by 3-5%. Under OCED guidance, TFD studies conducted in one country can be applicable to other countries if the characteristics of overlapping ecoregions are the same. These assessments are conducted using the OECD ENASGIPS tool. If these characteristics change, so will the similarity assessment and therefore the potential relevance of TFD sites. With increase rainfall, TFD sites in the Southeastern US, which typically have few similar areas, may become more relevant because other areas are getting wetter. Likewise, TFD sites in arid ecoregions may see a decrease in similarity scores. In this presentation we show that TFD studies in arid regions in the US remain relevant for foreseeable future.The objective of this assessment was to determine if climate change will impact the relevance of TFD studies and OECD ENASGIPS crosswalks ecoregion similarity scores. Specifically, we were interested in determining if ecoregions overlapping TFD sites remain the same over time in terms of precipitation, temperature, and ecoregion similarity. Both statistical analysis and ecoregion crosswalk assessments were conducted. In this presentation we will focus on an arid in California’s Central Valley using the intermediate IPCC RCP4.5 and worse case RCP8.5 climate change scenarios. Results indicate that under moderate climate change scenario the arid ecoregion has an increase in the number of similar ecoregion over time but a decrease is observed under the worse case scenario. In the short-term, 30 to 40 years, TFD studies are not predicted to see an impact by of climate change and data obtained from these TFD studies can be used for registration and reregistration of pesticides for the foreseeable future.

Authors:  Cornelis Hoogeweg, Amy Ritter, Raghu Vamshi, Dean Desmarteau (Waterborne).  SETAC Europe 2021.

PostersCrop Protection2021

Identification of Patterns in Mesocosm Data: An Analysis of Untreated Control Ecosystems Across Multiple Studies

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Session: Effect Modelling for Regulatory Environmental Risk Assessment of Chemicals: Where Are We and What Comes Next?

Abstract: For risk assessment, experimental mesocosms provide valuable insights into the complex responses of aquatic ecosystems to stressors. Similarly, aquatic systems models (ASMs) represent food web interactions in an aquatic species community and interactions with abiotic environmental conditions. In the context of a study to simulate mesocosms using ASMs, an analysis of control mesocosm data was conducted to identify patterns in temporal dynamics in the species communities. Control data from six mesocosm studies were anonymized, collated, and characterized using visual and statistical analyses. The data were generated during studies conducted in 2016, 2018 and 2019 by MESOCOSM GmbH. During these studies, physical parameters of temperature, oxygen, pH, water level and conductivity were measured over the study duration. Nitrate, ammonium, and phosphate concentrations and water hardness were measured prior to the beginning of each study. Additionally, weekly samples were collected for taxon and species abundance evaluation. The resulting dynamics of phytoplankton, periphyton, macrophytes, zooplankton and macroinvertebrates were analyzed for each study data set and across studies. Correlation matrices were constructed and used to examine the data and identify consistent patterns of biotic and abiotic interactions. The trends observed within and across the studies show considerable temporal variability in species composition and abundance. The characterization and understanding of similar and repeated temporal patterns in the untreated aquatic mesocosms is an important foundation for the simulation of mesocosm studies using ASMs. We provide perspectives on the challenges associated with variability observed in mesocosm controls, and offer possible explanation and insights for managing these challenges in modeling.

Authors: Farah Abi-Akar (Waterborne), Amelie Schmolke (Waterborne), Peter Ebke (Mesocosm GmbH), Jürgen Schmidt (Mesocosm GmbH), Nika Galic (Syngenta), Steven Bartell (Cardno), Isabel O’Connor (EBP), Simon Spycher (EBP), Nele Schuwirth (EAWAG), Tido Strauss (Gaiac), Damian Preziosi (Integral), Robert Pastorok (Integral), Roman Ashauer (Syngenta).  SETAC Europe 2021.