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PostersCrop Protection2015

Passerine Dietary (LC50) Test: Challenges and Utility in Deriving an Acute Endpoint for Pesticide Registration in the U.S.

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POSTER ID: WP066

PRESENTATION DATE: Wednesday, November 4, 2015

LOCATION: Exhibit Hall

ABSTRACT:

Since 2007, acute oral studies with passerine birds have been required for pesticide registration under the revised 40 CFR Part 158 data requirements. Many studies have been completed for new pesticide registrations or as part of the Registration Review data call-in (DCI) process. The primary challenge with the successful completion of an acute oral study is the propensity for passerine birds to regurgitate test material after administration via gavage or capsule. Approximately one-third of studies conducted to date have resulted in birds regurgitating the dose which can prevent determination of a definitive LD50. This can result in a regulatory data gap and presumed risk for passerine species. In 2012, EPA published guidance that provided alternatives for deriving an acute passerine endpoint when regurgitation is observed in the acute oral (LD50) study. Proposed alternatives include: testing additional passerine species, using the dose-level below that which regurgitation occurred as the acute endpoint, or conducting a sub-acute dietary (LC50) study (OCSPP Guideline 850.2200) using the species that presented the greatest regurgitation response in the acute oral toxicity test. The guidance indicates that the dietary concentration endpoint (LC50) will be converted to a dietary dose endpoint (dietary LD50) using the estimated ingested dose based on food consumption measured in the study. Although the avian acute oral guideline (OCSPP 850.2100) has recently been updated to address issues related to conducting acute oral toxicity tests with passerines, the current OCSPP 850.2200 only provides specific guidance for the testing of young northern bobwhite quail and mallard ducks. For passerine species, food avoidance over the 5-day period can lead to starvation confounding determination of toxic effects related to the test substance. In addition, food avoidance caused starvation in studies often results in similar dietary intake of the test substance across test concentrations leading to very flat slopes and inaccurate estimates of the dietary LD50. Food avoidance in this context results in the ingestion of a Maximum Tolerated Dose (MTD), where the dose appears to plateau thus potentially restricting the birds to insufficient food for their survival over the 5-day exposure period. Use of the MTD endpoint combined with the overall uncertainty in interpretation of the results from the dietary study are discussed in the context of the avian risk assessment process.

Max Feken, Syngenta; Twyla Blickley, Dow Agrosciences / ACES; Kristin Brugger, DuPont Crop Protection; Tiffany Carro, DuPont Crop Protection; Mark Christ, SynTech Research Laboratory Services; Peter Edwards, Syngenta Crop Protection LLC; Timothy Fredricks, Monsanto Company; Kevin Henry, NovaSource / Tessenderlo Kerley, Inc; Matthew Kern, Waterborne Environmental; Sean McGee, Bayer CropScience; Dwayne R.J. Moore, Intrinsik Environmental Sciences; Spencer Mortensen, Stephanie Plautz, BASF Corporation; Jane Staveley, Exponent; Faith Womack, Cheminova, Inc. “Passerine Dietary (LC50) Test: Challenges and Utility in Deriving an Acute Endpoint for Pesticide Registration in the U.S.”. SETAC Salt Lake City November 2015.

PostersVeterinary Medicines2015

Higher-Tier Surface Water Exposure Modeling Approach of Veterinary Pharmaceuticals Administered to Beef Cattle

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POSTER ID: WP210

PRESENTATION DATE: Wednesday, November 4, 2015

LOCATION: Exhibit Hall

ABSTRACT:

Watershed scale exposure modeling of veterinary pharmaceuticals in surface water was conducted following the U.S. Environmental Protection Agency’s (USEPA) Tier-2 drinking water pesticide exposure modeling approach. Three potential sources of veterinary pharmaceuticals administered to beef cattle were modeled – feedlots without runoff collection ponds (less than 1000 head), agricultural fields applied with manure collected from the feedlots, and pasture. Runoff and erosion from these sources were modeled and combined and inputted into a waterbody. The Pesticide Root Zone Model (PRZM) used in the FOCUS Surface Water and Groundwater model software (winPRZM) was modified to simulate a feedlot and pasture. PRZM 3.12 was used to model an agricultural field. EXAMS was used to model the surface waterbody (index reservoir), used by USPEA in drinking water risk assessments. Enhancements to winPRZM included having options to model timing of entry and exit of beef cattle on the feedlot and pasture and model constant mass of active ingredient in feedlots if degradation rate in manure in unknown. PRZM uses runoff curve number method for runoff estimation and USLE method for erosion estimation. The 90th percentile concentrations for peak, 4-day, 21-day, 60-day, 90-day and annual average exposure durations were estimated in the waterbody based on 30-year daily model and annual applications. The “application rates” of active ingredient to feedlot and pasture were estimated based on daily release rate of the active ingredient of the pharmaceutical in manure. The application rate of active ingredient in manure applied to agricultural land was based on daily release rate and phosphorus requirement of corn grain/silage. USEPA’s standard Tier-2 crop scenarios and weather files were used as such. The landscape metrics were derived from the GIS analysis of watersheds to estimate percent watershed area contributing to feedlots, pasture, and agricultural land applied with manure to model the watershed level index reservoir. The GIS analysis for estimation of percent contributions from each source is discussed in another poster titled “Spatial technologies to place veterinary medicine aquatic exposure concentrations into risk context” in this session.

Ishadeep Khanijo, Christopher Holmes, Amy Ritter, Joshua Amos, Mark Cheplick, W. Martin Williams, Waterborne Environmental.”Higher-Tier Surface Water Exposure Modeling Approach of Veterinary Pharmaceuticals Administered to Beef Cattle”. SETAC Salt Lake City November 2015.

PostersVeterinary Medicines2015

Spatial Technologies to Place Veterinary Medicine Aquatic Exposure Concentrations into Risk Context

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POSTER ID: WP221

PRESENTATION DATE: Wednesday, November 4, 2015

LOCATION: Exhibit Hall

ABSTRACT:

A case study in which spatial technologies were applied to characterize the potential for aquatic exposure from the excretion of beef cattle treated with veterinary pharmaceuticals will be demonstrated following techniques similar to the higher tiers of USEPA’s aquatic exposure framework. GIS was used to establish high versus low risk regions of exposure potential across the US. Multiple regions representing a variety of beef cattle characteristics and climatic conditions were identified as having the highest vulnerability potential. From within each region, a single vulnerable watershed was selected for watershed-scale modeling. The importance of the watershed selection places is that it places the modeling results into national context and promotes confidence that the results represent a realistic intense-use scenario that can be applied to other U.S. beef regions. For each watershed modeled, local factors relevant to simulating veterinary medicines in surface water were identified using spatial data on feedlot densities, pastured cattle lands, and croplands treated with manure. While a fate and transport model ultimately calculated the concentration of drug in the environment, GIS was used to measure the distribution of landscape factors influencing exposure and place the concentrations into the larger national risk perspective. The workflow to achieve a representative watershed for higher tier modeling will be presented. Examples using geospatial data to define vulnerability at the region and watershed scales will be discussed. Refer to the poster (in the same session) titled, “Higher-tier surface water exposure modeling approach of veterinary pharmaceuticals administered to beef cattle” for a detailed view of how USEPA’s Pesticide Root Zone Model (PRZM) was modified to simulate transport of the manure-bound drug to surface water.

Joshua Amos, Ishadeep Khanijo, Christopher Holmes, Mark Cheplick, W. Martin Williams, Amy Ritter, Waterborne Environmental; Joseph Robinson, Zoetis.”Spatial Technologies to Place Veterinary Medicine Aquatic Exposure Concentrations into Risk Context”. SETAC Salt Lake City November 2015.

PostersAgriculture and Food, Home and Personal Care Products, Industrial and Specialty Chemicals2015

Green-washing: What Is a Meaningful Ecolabel

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POSTER ID: WP217

PRESENTATION DATE: Wednesday, November 4, 2015

LOCATION: Exhibit Hall

ABSTRACT:

Currently there are over 400 ecolabels for food and consumer products in the global marketplace. These labels are marketing efforts informing the purchaser of a variety of claims of sustainability measures enacted by companies. The marketplace is flooded with several similar claims on whether a product is less hazardous, sustainable, organic, non-GMO, fair-trade, recyclable, recycled, carbon neutral, or biodegradable. Generally there are four types of labels in order of volume, 1) voluntary environmental certification programs, 2) self- or 3) cause-related claims and 4) governmentally regulated. The federal, some state, and International governments have limited direct roles in ecolabeling beyond mandatory hazard warning (e.g., pesticide or Prop. 65) or informational disclosures (EPA fuel economy, certified organic, WaterSense, or Energy Star). There are several third-party certification and quasi-governmental programs that lend credibility to an ecolabel; however, standardization or centralization of these programs are lacking. Several seals of approval overlap in required data for certification; however, a comprehensive comparison of each standard has not been performed. The US EPA and GAO are reviewing the Environmentally Preferable Purchasing program currently by reviewing a subset of ecolabeling in regards to building paints/coatings/removers, building flooring, and furniture; however, implications towards the general public are unknown. Several questions arise when considering comparison of ecolabeling standards. What would be the best way to implement meaningful change to ecolabel marketing? Develop a list and score each label? Who will collect the information and develop trustworthy comprehensive scoring standards for each product sector? How to engage all stakeholders to agree on the standards? Finally how does all the data collection conform to expanding regulations such as Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH), Restriction of Hazardous Substances (RoHS) Directive, California’s Safer Consumer Products, and Washington’s Chemicals of High Concern to Children?

Nikki Maples-Reynolds, Duane Huggett, Waterborne Environmental.”Green-washing: What Is a Meaningful Ecolabel”. SETAC Salt Lake City November 2015.

PostersCrop Protection2015

Using Generic Population Models to Evaluate the Potential for Adverse Effects in Endangered Species Risk Assessment: A Case Study Approach

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POSTER ID: WP214

PRESENTATION DATE: Wednesday, November 4, 2015

LOCATION: Exhibit Hall

ABSTRACT:

Population modeling can help evaluate exposure and effects of pesticides in an ecologically relevant context for species identified as potentially affected in the screening-level stages of an endangered species assessment. However, screening-level assessments at the national scale may initially identify a large number of potentially-affected species based on proximity of species habitat and pesticide exposure. A practical solution to address this challenge is the development of “first-tier” generic population models based on species groups with common exposure/effects and life history characteristics. We present case studies detailing the process of implementing national-scale generic population models across multiple ecological guilds (e.g., fish and birds) for a pesticide. By using key ecological parameters to differentiate between species groups, generic population models can be developed to conservatively evaluate population-level impacts of pesticides for representative species. Generic models were developed to describe population dynamics alternatively sensitive to (1) early life stage survival, (2) intermediate age survival, and (3) reproduction (fecundity). The generic models were used to help screen large numbers of representative endangered species in the initial phases of national scale assessments in several case study applications. This first-tier modeling approach can identify individual species that may require further analysis using species-specific higher-tier modeling, thus offering a pragmatic approach to focus assessment efforts and resources on the species with greatest actual risk. Our case study analysis demonstrates the practicality and effectiveness of applying ecological modeling (e.g., model selection and implementation) as part of a tiered strategy for adding ecological context and advancing the interpretation and efficacy of endangered species risk assessments.

Katherine Kapo, Matthew Kern, Daniel Perkins, Waterborne Environmental; Valery Forbes, Amelie Schmolke, University of Minnesota; Steven Bartell, Cardno Entrix; Robert Pastorok, Integral Consulting, Inc. “Using Generic Population Models to Evaluate the Potential for Adverse Effects in Endangered Species Risk Assessment: A Case Study Approach”. SETAC Salt Lake City November 2015.

PresentationsCrop Protection2015

Bringing Ecological Context to Endangered Species Risk Assessments Using Population Modeling: Challenges, Opportunities, and a Path Forward

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PRESENTATION ID: 440

PRESENTATION DATE: Wednesday, November 4, 2015 at 8:00AM

LOCATION: Ballroom G

ABSTRACT:

Current screening-level stages of endangered species pesticide risk assessments rely on conservative estimation of exposure and effects based on spatial proximity of species habitat to locations of pesticide use and conservative effects thresholds (such as “1-in-a-million” individual mortality). These screening-level thresholds are designed to be highly protective, but are essentially arbitrary from an ecological standpoint. Despite subsequent refinements to the exposure and effects assessment (e.g., more realistic exposure views, species surrogacy and refined habitat delineation), it remains a challenge to interpret the risk of adverse effects to a species in an ecologically meaningful way. Population modeling has been recommended in the final steps of an assessment as an approach for providing greater ecological context through extrapolation of individual-level effects to outcomes relevant at the population-level. Given the large number and diversity of species involved in national-scale pesticide risk assessments, we propose a pragmatic tiered strategy for population modeling that aims to incorporate ecological relevance into risk decision criteria as early as possible in an assessment. We present a tiered approach where “generic” population models representative of species groups with common life history characteristics are applied in the early stages of an assessment to provide ecological context to screening-level thresholds. This first tier of population modeling can be useful to inform risk decision criteria and identify species which may require further evaluation using more complex (and resource-intensive) higher-tier population models. Using concrete examples, we describe how strategic data organization and exposure/effects refinements can effectively be combined with established population modeling approaches to add meaningful ecological perspective to pesticide risk decision criteria at each tier of a risk assessment. Successful management of endangered species will require development of a risk assessment framework that is scientifically robust and pragmatic.

Katherine Kapo, Matthew Kern, Daniel Perkins, Waterborne Environmental; Valery Forbes, Amelie Schmolke, University of Minnesota; Steven Bartell, Cardno Entrix; Robert Pastorok,  Integral Consulting, Inc.”Bringing Ecological Context to Endangered Species Risk Assessments Using Population Modeling: Challenges, Opportunities, and a Path Forward”. SETAC Salt Lake City November 2015.

PostersCrop Protection2015

The Impact of Variability in Non-Target Terrestrial Plant Studies on Endpoint Selection

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POSTER ID: TP048

PRESENTATION DATE: Tuesday, November 3, 2015

LOCATION: Exhibit Hall

ABSTRACT:

Inherent variability in non-target terrestrial plant testing is an ongoing issue with respect to the use and interpretation of these data for risk assessment. These standardized study guidelines were initially designed to calculate ER25 values for various effect measures, including sub-lethal measurements of growth. Statistical differences from control groups are often a product of natural variability, with no apparent biological consequence associated with these differences. This can lead to a requirement to conduct tier-2 studies with some species, the appearance of non-monotonic dose-response curves which are simply natural variability in the data, or an assumption of risk when there are statistical differences from controls of even a few percent. This issue has recently been associated with the requirement to generate a NOER for each study type for use in endangered species assessments. The 2012 U.S. EPA Ecological Effects Test Guidelines (OCSPP 850.4100 and 850.4150) further state that if a NOER (NOEC) cannot be determined, the dose at which there is a 5% effect should be estimated and used instead. The attempt to derive a NOER or 5% effect level and the associated risk assessment conclusions drawn from these values, which may simply represent natural biological variability, can overestimate risk. To address this concern, we evaluated historical data from standard seedling emergence and vegetative vigor studies to determine the variability in the controls for shoot height and shoot weight. Results were compiled for each combination of study type, species, and effect measure. Our findings indicate the effect level that can be reliably determined as being significantly different from the controls for each combination of species and effect measure and by what statistical test. In addition, we discuss the size effect that can be estimated reliably from regression models and the uncertainties arising from model selection.

Jane Staveley, Josie Nusz, Exponent; Daniel Edwards, BASF Corporation; John Green, DuPont / Applied Statistics Group; Kevin Henry, NovaSource / Tessenderlo Kerley, Inc.; Matthew Kern, Waterborne Environmental.”The Impact of Variability in Non-Target Terrestrial Plant Studies on Endpoint Selection”. SETAC Salt Lake City November 2015.

PostersCrop Protection2015

Selection of Effects Data for National Scale Pesticide Endangered Species Assessments

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POSTER ID: MP091

PRESENTATION DATE: Monday, November 2, 2015

LOCATION: Exhibit Hall

ABSTRACT:

The selection of appropriate toxicity endpoints used in an endangered species risk assessment is a critical phase in the analysis. A significant amount of toxicity data for non-target species is generated to support regional and global pesticide registrations as required by multiple regulatory authorities. Additionally, data from peer reviewed literature may also be available that can be used in the effects characterization. Determining a method for how this data will be considered prior to starting the assessment can is essential. A species surrogacy analysis can be one effective tool in selecting toxicity data that is most relevant for use in risk assessment for federally listed species. The core of this analysis is to make taxonomic associations between the species used in available toxicity studies with those listed species being considered in the assessment. This involves organizing listed species and laboratory species taxonomically and matching those species with the greatest taxonomic similarities. This analysis provides a better alternative to simply selecting a single laboratory species to represent the assumed toxicity of large groups of listed species. As part of this analysis, the relevance of experimental designs used for the toxicity studies should be considered prior to making species surrogacy conclusions. Information such as route of exposure, study duration, concentration/dose tested, endpoints measured and dose response relationships must all be considered. Additionally, species habitat requirements and other life history characteristics can be evaluated to help define species surrogacy assignments. Scientific judgment and data quality assessments are required to select surrogate toxicity data that best represents listed species in the endangered species risk assessment. Where possible, uncertainty in surrogacy assignments should be captured in the analysis. This presentation provides an example of how such methodology can be incorporated into a national-scale endangered species assessment.

 

Matthew Kern, Katherine Kapo, Waterborne Environmental; Alan Samel, DuPont Crop Protection.”Selection of Effects Data for National Scale Pesticide Endangered Species Assessments”. SETAC Salt Lake City November 2015.

PostersCrop Protection2015

A National Scale Threatened and Endangered Species Risk Assessment Process to Prioritize Assessment Refinements for Insecticide Use Patterns

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POSTER ID: MP087

PRESENTATION DATE: Monday, November 2, 2015

LOCATION: Exhibit Hall

ABSTRACT:

A national scale endangered risk assessment requires consideration of a large amount of effects and exposure data related to over 1500 listed species. An efficient and pragmatic tiered approach offers a means of effectively focusing risk management efforts on species at greatest risk while minimizing resources expended on those not at risk from a pesticide. Without effective screening, these assessments may overwhelm the available resources and limit the ability to adequately protect species from stressors that pose the greatest risk to their continued existence and recovery. Screening level risk assessments can be very effective in this prioritization process at the initial steps, provided the methods allow for the incorporation of reasonable descriptions of habitat and effects. In these generally protective initial steps, the assessment endpoint should consider the overall protection goal and the result of combining protective effects and exposure methods. Once an effective screening assessment has been completed, more sophisticated methods can be applied to provide a better risk characterization and increased certainty around risk conclusions for cases where the potential for risk has been established. The selection of effects data, exposure modeling estimates and geospatial species and use site locations should be directed towards a risk characterization that gives a risk manager an index for the likelihood and significance of an estimated effect on the species. We present a novel tiered approach designed to integrate established endangered species risk assessment methodologies, knowledge from FIFRA risk assessments and higher risk analysis techniques. Examples are incorporated to illustrate these methods and to move the evaluation towards a probabilistic expression of risk relevant to listed species.

Matthew Kern, Nathan Snyder, Waterborne Environmental; Aldos Barefoot, Mark Holliday, DuPont Crop Protection. “A National Scale Threatened and Endangered Species Risk Assessment Process to Prioritize Assessment Refinements for Insecticide Use Patterns”. SETAC Salt Lake City November 2015.

PostersCrop Protection2015

Refined Aquatic Exposure Methods for Species Focused Threatened and Endangered Species Risk Assessments

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POSTER ID: MP090

PRESENTATION DATE: Monday, November 2, 2015

LOCATION: Exhibit Hall

ABSTRACT:

Standard tiered exposure methods allow for screening level deterministic risk assessments in the FIFRA framework. With additional sensitivity endpoints established for threatened and endangered species, the standard tools, even when refined with aquatic bins, often lead to unresolved risk concerns. Several case studies will be presented that use species specific data on habitat and biology to establish refined exposure estimates relevant to the listed species for use in a species focused ecological risk assessment. Species in groups such as cave dwelling aquatic invertebrates, river mussels, and isolated vernal pool systems require different aquatic exposure tools (leaching models, watershed scale models, edge-of-field models with downstream dilution, etc.) and an integration of these tools with species focused landscape refinements, knowledge of proposed uses and the incorporation of existing federal protections. The refined exposure estimation, integrated with surrogate species dose response curves or species sensitivity distributions for multiple surrogates, results in a species focused probabilistic risk expression.

Nathan Snyder, Kevin Wright, Joshua Amos, Waterborne Environmental; Aldos Barefoot, Dupont Crop Protection. “Refined Aquatic Exposure Methods for Species Focused Threatened and Endangered Species Risk Assessments”. SETAC Salt Lake City November 2015.