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# Overview of the Endocrine Disruptor Screening Program

Mary Manibusan, Director Endocrine Disruptor Screening Program Office of Science Coordination and Policy

# EDSP Program Overview:

 Mission of the Endocrine Disruptor Screening Program: FFDCA and SDWA 1996

 Recommendations of the Endocrine Disruptor Screening and Testing Advisory Committee, 1998

 Program Implementation: Data Review Process “Roadmap”

 Current State of the Science: 2013 FIFRA Scientific Advisory Panel Reviews

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# EDSP Mission

To protect public health and wildlife by screening and testing chemicals and taking appropriate actions for those chemicals that are found to have endocrine effects.

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# Legislative Mandate

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###  1996 Federal Food, Drug and Cosmetic Act, section 408(p) Requires the U. S. EPA to develop a screening program using appropriate validated test systems and other scientifically relevant methods to determine whether certain substances may have an effect in humans that is similar to an effect produced by a naturally occurring estrogen, or other such endocrine effect as the Administrator may designate.

 1996 Safe Drinking Water Act Amendments, section 1457 Testing of chemical substances that may be found in sources of drinking water, if substantial human populations may be exposed.

# Endocrine Disruptor Screening and Testing Advisory Committee (EDSTAC), 1998

EDSTAC Key Recommendations:

 Expand Protection to Include Human Health and Wildlife

 Include Estrogen, Androgen and Thyroid Pathways

 Develop a Two

- Tiered S creening and Testing P rogram:



# EDSTAC Conceptual Framework: Tier 1 Screening for Potential to Interact Potential to interact with the estrogen, androgen or thyroid hormone systems 

## Tier 2 Testing to determine Interaction with the endocrine system

If endocrine

- mediated adverse effects then quantify dose

- response relationship

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# EDSP Tier 1 Screening Battery, 2008

**In vitro**

Estrogen Receptor (ER) Binding Estrogen Receptor Transcriptional Activation Assay (ERTA) Androgen Receptor (AR) Binding Steroidogenesis

Aromatase 

# In vivo
Uterotrophic (rat) Hershberger (rat) Pubertal Female (rat) Pubertal Male (rat) Amphibian Metamorphosis Assay (frog)
Fish Short

- Term Reproduction Assay (fish)Synthesis Steroid

X X X X X Pubertal female **In vivo In vitro** 

X ER Transcriptional Activation

X X HPT

X X HPG

X Aromatase (Recombinant)

X Uterotrophic

X X Hershberger

X X X Pubertal male X X Steroidogenesis (H295R) X X AR Binding X X ER Binding E T A

- A E

- E

Amphibian Metamorphosis X X X X X X Fish Reproductive Screen Synthesis Steroid

X X X X X Pubertal female **In vivo In vitro** 

X ER Transcriptional Activation

X X HPT

X X HPG

X Aromatase (Recombinant)

X Uterotrophic

X X Hershberger

X X X Pubertal male X X Steroidogenesis (H295R) X X AR Binding X X ER Binding E T A

- A E

- E

Amphibian Metamorphosis X X X X X X Fish Reproductive Screen 

# EDSP Tier 1 Screening Assays

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# Proposed EDSP Tier 2 Test Methods

**Mammalian**

Mammalian Two

- Generation Reproduction (Rat) Extended One Generation Reproduction (Rat) 

# Ecological

Avian Multi

- Generation Reproduction (Japanese quail) Larval Amphibian Growth and Development (Xenopus laevis)
Fish Multi

- Generation Reproduction (Medaka)
Invertebrate Multi

- Generation Reproduction (Mysid and Copepod)Slide 9 of X 

# Comparison of Tier 1 and Tier 2

Tier 1 Screening

 Shorter term and Lower Cost

 Minimize False Negative

 Potential to Interact (y/n)

 Limited Doses

 In vitro and In vivo

 Battery

– all 11 assays Tier 2 Testing

 Longer term, definitive studies

 Interaction and dose

 Dose Response

 In vivo: Multiple Taxa

 Targeted testing

# From Prioritization to Screening and Testing: EDSP RoadmapJanuary SAP 

## Step1: 
Prioritization of Chemicals for Tier 1 Screening using effects based chemical categorization and exposure data.May and July SAP 

## Step 2: Tier 1 assay data review Step 3: weight of evidence determinations with other scientifically relevant dataJune SAP 

## Step 4: Tier 2 Assays Data review Multigeneration reproduction studies

Slide 10 of X Step 1: Prioritization of EDSP Universe of Chemicals: SAP January 29

- 31 st , 2013 Step 2: Tier 1 assay and battery: SAP May 21

- 23 rd , 2013 Step 3: Weight of Evidence Review: SAP July 30

- August 2, 2013 Step 4: Validation of Tier 2 test methods: SAP June 25

- 28, 2013

# Step 1: Chemical Prioritization: FIFRA SAP January 29

- 31, 2013

 Focus and Objective:
1. Prioritization of the universe of chemicals for estrogen receptor adverse outcome pathway using computational toxicology tools

2. To obtain input and recommendations on the scientific concepts, principles and processes used to prioritize chemicals for EDSP screening.

Slide 11 of XEDSP Universe of Chemicals n= 10,341

Chemical Lists FIFRA Registration Review Schedule for Active Ingredients (Approx.=1500) SDWA and INERTS (Approx.=9000)

Physico

Chemical Properties

(Approx n=5000) 

## Excluded

Exposure Potential

SDWA 

## Lower Priority

ER Expert System

High through put system 

## Prioritized List of Chemicals for EDSP Tier 1 Screening yes

No * Mixtures will be lower priority

no

Yes Considerations of Read

Across and Chemical Categories

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# January SAP Step 1: Chemical Prioritization Method

# Step 2: FIFRA SAP May 21

- 23, 2013

 Focus and Objective:

• 1. Performance of EDSP Tier 1 Individual Assays

• 2. Performance of the EDSP Tier 1 Battery

“ Convene a panel of independent scientists to review all the screening data for 50

- 100 compounds, with an eye towards revising the process and eliminating those methods that don’t work.” (SAB/SAP panel in 1999)

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# SAP 2008: Tier 1 Battery Review

 Open and transparent public process for independent, external scientific peer review

 Based on current state of the science, Tier 1 assays and battery are capable of identifying potential E, A, T endocrine activities.

 Appropriate starting point to detect potential endocrine disruptors

 Multiple taxa and mode of action endpoints provide a range of metabolism and needed corroboration

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# SAP 2013: Tier 1 Assay Review

 21 chemicals selected for this evaluation: a range of physico

- chemical properties and biological activity

 Tier 1 assays provide useful information to evaluate potential interactions with the E, A, and T signaling pathways.

 No major problems identified with the Tier 1 assays

 Laboratories were able to execute each assay protocol in accordance with the respective test guidelines and achieve the specified performance criteria.

 Some minor deviations from the performance criteria, but differences were not substantial

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# SAP 2013: Tier 1 Battery Review

 Thyroid: AMA and the rat pubertal studies can provide different types of information and it reinforces the importance of including both taxa in the screening battery to reduce the potential for false negatives.

 Androgen : in vitro assays do not consistently exhibit significant effects when effects are observed in the in vivo assays. Possible redundancy across the in vivo assays (Hershberger, male pubertal, and FSTRA), albeit some with observation of overt toxicity

 Estrogen: female rat pubertal and fish assays are important in evaluating the E pathway across taxa. The uterotrophic assay was consistently negative for all the chemicals. Note: no representative estrogen agonist in the subsample.

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# Fundamental Charge to the Panel

1. Overall comment on the assay (laboratory) performance and advice on how to address technical deviations and other issues encountered with specific assays. 2. Overall comment on the Tier 1 battery performance and whether there are unnecessary redundancies among the 11
assays.

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## The whole is greater than the sum of its parts.” Aristotle

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# Acknowledgements:

1. Jess Rowland, OPP 2. Gregory Akerman, OPP 3. John Liccione, OPP 4. Amy Blankinship, OPP 5. Catherine Aubee, OPP 6. Thomas Steeger, OPP
7. Vicki Dellarco, OPP 8. Patience Browne, OSCP 9. Don Bergfelt, OSCP 10. Calvin Powell, OPP

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# USEPA Presentations

Background: Current Validated EDSP Tier 1 Screening Assays and Battery, Leslie Touart, Ph.D

. , Exposure Assessment Coordination and Policy Division, Office of Science Coordination and Policy, EPA

In Vitro Assays, Gregory Akerman, Ph.D., Health Effects Division, Office of Pesticide Programs, EPA

In Vivo Mammalian Assays, John Liccione, Ph.D., Health Effects Division, Office of Pesticide Programs, EPA

Fish Assay, Amy Blankinship, M.S., Environmental and Fate Effects Division, Office of Pesticide Programs, EPA

Frog Assay, Catherine Aubee, M.P.A., Environmental and Fate Effects Division, Office of Pesticide Programs, EPA

Battery Performance, Tom Steeger, Ph.D , Catherine Aubee, M.P.A, . Amy Blankinship, M.S., Gregory Akerman, Ph.D.,

Overall Summary of Assay and Battery Review, Tom Steeger, Ph.D., Environmental and Fate Effects Division, Office of Pesticide Programs, EPA

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