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PostersHome and Personal Care Products2015

Development of iSTREEM® 2.0, New Enhancements for Down-The-Drain Model to Support Environmental Exposure Assessments across Multiple Commodity Groups

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PRESENTATION ID: RP046

PRESENTATION DATE: Thursday, November 5, 2015

POSTER LOCATION: Exhibit Hall

ABSTRACT:

The iSTREEM® model (“in-stream exposure model”), a free and publically-available web-based model supported by the American Cleaning Institute (istreem.org), provides a means to estimate chemical concentrations in effluent, receiving waters, and drinking water intakes (DWI) across the conterminous U.S. as well a number of watersheds in Canada under mean annual and low-flow (7Q10) conditions. This presentation will discuss recent upgrades made to enhance the model, underlying data, algorithm and presentation of results leading to the release of iSTREEM® 2.0. iSTREEM® 2.0 incorporates geographic locations of over 12,000 wastewater treatment plant (WWTP) facilities along a U.S.-wide river network of effluent-impacted river reaches, providing a framework to integrate geographic data to assess environmental risk for multiple scenarios of interest. WWTP facilities and associated facility level information were derived from the latest available USEPA Clean Watershed Needs Surveys. The river network used by iSTREEM® 2.0 was upgraded from previous iSTREEM® versions to a higher-resolution hydrologic dataset based on the NHDPlus version 2, which includes estimated mean annual and low flow (7Q10) data based on USGS stream gage measurements. The relationship between WWTP facilities and DWI locations to the river network was established applying techniques developed by USEPA. Pre-calculation of certain data and efficiency improvements to model algorithm has enabled simulation runs to complete in significantly less time compared to prior versions of the model. Model results are presented in a standardized manner for consistent results communication across all users, and are provided in a readily usable format (MS Excel) for easy interpretation and further customization of result presentation. Major assumptions used in constructing the model will be discussed. Recent upgrades and developments are geared to expand adoption of the model by a wide variety of users as an environmental risk assessment tool across multiple commodity groups (personal care products, pharmaceuticals, food additives, pesticides, etc.) that require internal or regulatory environmental assessments. The discussion will also include a comparison of model results between the prior version of iSTREEM® and latest iSTREEM® 2.0 to examine the impact of recent upgrades on the national distribution of predicted environmental concentrations (PEC’s) across the U.S.

Raghu Vamshi, Katherine Kapo, Megan Sebasky, Christopher Holmes, Waterborne Environmental; Paul DeLeo, Darci Ferrer,American Cleaning Institute. “Development of iSTREEM® 2.0, New Enhancements for Down-The-Drain Model to Support Environmental Exposure Assessments across Multiple Commodity Groups”. SETAC Salt Lake City November 2015.

PostersIndustrial and Specialty Chemicals2015

Hepatic Biotransformation of 14C-Decamethylcyclopentasiloxane (D5) and 14C-Decamethyltetrasiloxane (L4) in Fish, Birds and Mammals

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POSTER ID: RP028

PRESENTATION DATE: Thursday, November 5, 2015

LOCATION: Exhibit Hall

ABSTRACT:

When considering bioconcentration (BCF), bioaccumulation (BAF) and trophic magnification (TMF) assessments, biotransformation and elimination of a chemical are important processes within an organism to understand. Recent efforts have been made in extrapolating in vitro fish biotransformation data to a whole body BCF value in an effort to better guide the need for an OECD 305 fish bioconcentration study. By integrating biotransformation estimates into BCF models, a more realistic estimation of BCF can be calculated while providing a cost-effective assay that uses less vertebrate animals. Building on this single species extrapolation concept, biotransformation data from multiple species may be used to construct a biomagnification or trophic magnification model for a given chemical. Using 14C radiolabelled compounds and high performance liquid radiochromatography, in vitro metabolism data utilizing liver microsomes were developed for a cyclic siloxane, D5, and a linear siloxane, L4. Of the species investigated, mink demonstrated the greatest potential to biotransform D5 and L4 siloxane. 14C radiochromatograms show the loss of D5 and L4 siloxane, as well as increases in metabolite production over the 60 min incubation period. The percentage loss of D5 was similar with human and rat microsomes and greater then observed with fish. The percentage loss of D5 in birds is low compared to fish and mammals. Similar relationships for loss of parent hold true for L4 (kestrel data not available). These data suggest that D5 and L4 siloxane are biotransformed by a wide array of species, which can influence “B” assessments. In addition, these data can be used to estimate whole-body rates of metabolism for incorporation into predictive environmental assessments.

Duane Huggett, Waterborne Environmental; Mark Cantu, David Hala, University of North Texas; Jeanne Domoradzki, Debra McNett,Dow Corning Corporation.”Hepatic Biotransformation of 14C-Decamethylcyclopentasiloxane (D5) and 14C-Decamethyltetrasiloxane (L4) in Fish, Birds and Mammals”. SETAC Salt Lake City November 2015.

PostersHuman Pharmaceuticals2015

Framework for Addressing Bioaccumulation Potential of Human Pharmaceuticals

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POSTER ID: RP027

PRESENTATION DATE: Thursday, November 5, 2015

LOCATION: Exhibit Hall

ABSTRACT:

The potential for human pharmaceuticals to bioaccumulate in aquatic organisms is rapidly becoming an area of scientific and regulatory interest. Historically, bioaccumulation assessments are conducted after consideration of a chemical’s hydrophobicity (e.g. Kow). The current strategy for determining the bioaccumulation potential of a human pharmaceutical is identical in scope in that scientists are required to conduct an OECD 305 fish study if the Kow value of a given pharmaceutical is greater than a prescribed regulatory trigger value (e.g. Log Kow> 4). The physical-chemical knowledge (e.g. pKa) of the compound should be incorporated into this initial Kow assessment to better guide the need for a full “B” assessment. In many instances, the current strategy does not utilize the wealth of non-clinical and clinical data available on the absorption, disposition, metabolism and elimination (ADME) of the pharmaceutical of interest, which could be used to better inform scientists on important characteristics and physiological processes associated with that human pharmaceutical. It is important to recognize that fish have the ability to perform many of the same physiological processes that mammals perform, hence a pharmaceutical’s ADME characteristics could be similar in fish. These data can be used to understand the ability of a fish to absorb, distribute, biotransform and eliminate a human pharmaceutical. If needed, studies can be conducted utilizing methodologies widely used on the drug development process (e.g. in vitro metabolism assays) to understand the similarity between fish and mammals and better guide the testing overall strategy. By utilizing all the available information collected and methodologies employed during the drug development process of a human pharmaceutical, scientists can make a more informed decision regarding the need for bioaccumulation testing (i.e. OECD 305), potentially reduce the number of vertebrate animals used in laboratory studies and achieve an overall cost savings.

Duane Huggett, Nikki Maples-Reynolds, Waterborne Environmental. “Framework for Addressing Bioaccumulation Potential of Human Pharmaceuticals”. SETAC Salt Lake City November 2015.

PostersCrop Protection2015

An Evaluation of Endpoint Sensitivity for Benthic Invertebrate Chronic Toxicity Tests

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POSTER ID: RP021

PRESENTATION DATE: Thursday, November 5, 2015

LOCATION: Exhibit Hall

ABSTRACT:

On October 26, 2007, sediment toxicity testing with benthic aquatic invertebrates became a conditional requirement as part of the Office of Pesticide Program’s ecological effects data requirement contained in 40 CFR Part 158 Subpart G. This action led to efforts to improve the consistency of test performance and streamline chronic life-cycle test methods with benthic invertebrates. A focal area of discussion pertaining to these efforts included critically evaluating the relative sensitivities of required test endpoints within tests and among tests with different species as well as the utility of specific endpoints for defining biological thresholds of effects associated with contaminant exposure. To provide clarity in these pursuits, it is also important to consider variability within control responses as the value of monitoring more sensitive endpoints may be muted by reduced statistical power due to high variability within some endpoints (perhaps associated with natural biological variability). In addition to exploring relative endpoint sensitivity, determining possible data redundancy associated with endpoint overlap is also critical for improving confidence for defining effects threshold based on these test endpoints and may also help manage laboratory resources. The Sediment Subcommittee of Crop Life America has compiled detailed data from chronic sediment toxicity tests with Chironomus dilutus, Hyalella azteca and Leptocheirus plumulosusbased on current USEPA draft test guidelines and this presentation provides an overview of the data analysis for these species. Key findings from this data evaluation will be reported in this presentation, along with recommendations for streamlining endpoints.

Jennifer Gates, Mark Cafarella, Waterborne Environmental; Ted Valenti, Syngenta; Bibek Sharma, FMC Corp Global Regulatory Sciences; Michael Bradley, Smithers Viscient; Alan Samel, DuPont Crop Protection; Jane Staveley, Exponent; Sean McGee, Bayer CropScience LP; Maike Habekost, BASF; Hank Krueger, Wildlife International.”An Evaluation of Endpoint Sensitivity for Benthic Invertebrate Chronic Toxicity Tests”. SETAC Salt Lake City November 2015.

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.