《植物化学保护》课程教学资源（英文讲稿）A New Toxicology Testing Paradigm：Meeting Common Needs

Steven Bradbury,Director Environmental Fate and Effects Division Office of Pesticide Programs US Environmental Protection Agency National Pesticide Program A New Toxicology Testing Paradigm: Meeting Common Needs National Pesticide Program MISSION Best Possible Regulatory Decisions to Protect Public Health and the Environment Rely on All Available and Relevant Scientifically Sound Information

1 National Pesticide Program A New Toxicology Testing Paradigm: Meeting Common Needs Steven Bradbury, Director Environmental Fate and Effects Division Office of Pesticide Programs US Environmental Protection Agency 2 • Best Possible Regulatory Decisions to Protect Public Health and the Environment • Rely on All Available and Relevant Scientifically Sound Information National Pesticide Program MISSION

National Pesticide Program OPP AT A GLANCE Gateway to pesticide market,where sales over $11 B/yr Over 5,000 regulatory decisions annually Approximately 1,100 active ingredients and 19,000 products Reevaluation of existing pesticides on a regular schedule to ensure safety standards continue to be met National Pesticide Program OPP AT A GLANCE Safety Evaluation Done for all Pesticide Chemicals -Agricultural chemicals -Antimicrobials and Consumer products -Inert ingredients Data Availability/Quality Varies Extensively New Risk Assessment/Management Challenges Always Arise

2 3 • Gateway to pesticide market, where sales over $11 B/yr • Over 5,000 regulatory decisions annually • Approximately 1,100 active ingredients and 19,000 products • Reevaluation of existing pesticides on a regular schedule to ensure safety standards continue to be met National Pesticide Program OPP AT A GLANCE 4 National Pesticide Program OPP AT A GLANCE • Safety Evaluation Done for all Pesticide Chemicals – Agricultural chemicals – Antimicrobials and Consumer products – Inert ingredients • Data Availability/Quality Varies Extensively • New Risk Assessment/Management Challenges Always Arise

National Pesticide Program CHALLENGES Science Increasingly Complex and Changing Large Number of Chemicals to Review with Many Possible Adverse Outcomes Finite Resources and Time Sufficient,Credible Information to Make a Decision, not an Overwhelming Amount of Information Public Expectations for Scientific Soundness, Transparency,and Timeliness National Pesticide Program Vision for a New Toxicology Testing and Assessment Paradigm ·Integrative ·Hypothesis-Driven ·Efficient

3 5 National Pesticide Program CHALLENGES • Science Increasingly Complex and Changing • Large Number of Chemicals to Review with Many Possible Adverse Outcomes • Finite Resources and Time • Sufficient, Credible Information to Make a Decision, not an Overwhelming Amount of Information • Public Expectations for Scientific Soundness, Transparency, and Timeliness 6 • Integrative • Hypothesis-Driven • Efficient National Pesticide Program Vision for a New Toxicology Testing and Assessment Paradigm

Why a Shift in Paradigm? ·b8ee8bt88emg5R6mesomcn Increase efficiency by focusing the regulated ific effec to assess and manage risks appropriately e8Cga8a9Rg8t8esw6es8g on all possible adverse outcomes Why a Shift in Paradigm? Lower the costs for the government and taxpavers because the Agency could avoid reviewing unnecessary fests Eliminate complex and expensive in vivo testing for the pesticide-producing industry Reduce the use of animals in testing

4 7 Why a Shift in Paradigm? • Improve ability to carry out EPA mission of protecting public health and the environment • Increase efficiency by focusing the regulated community, government, and interested parties on a pesticide’s most likely hazards of concern
Determine what specific effects data for each chemical and exposure situation are essential to assess and manage risks appropriately
Use screening and priority setting to eliminate the need for requiring a battery of tests focused on all possible adverse outcomes 8 Why a Shift in Paradigm? • Lower the costs for the government and taxpayers because the Agency could avoid reviewing unnecessary tests • Eliminate complex and expensive in vivo testing for the pesticide-producing industry • Reduce the use of animals in testing

Current Paradigm Risk Managers Focus on Potential Adverse Outcomes Mortality Reproductive Developmental Fertility BATTERY of Animal Testing (Part 158) Current Toxicology Testing Paradigm Generates In Vivo Animal Data for all Possible Outcomes to Determine which of all Possible Effects are Relevant Implementing Change Development and implementation of a new,integrated approach to the testing and assessment of pesticides will be a challenge and will take place over the next 10 years .Scientific tools and knowledge must be 8iae86R8beee6eegdngana National Academy of Science study 、分

5 9 Mortality •Systemic Toxicity •Disease •Cancer Reproductive Fitness •Viable Offspring •Fertility Developmental Impairment •Terato •Prenatal Deficits Current Paradigm • Risk Managers Focus on Potential Adverse Outcomes • Current Toxicology Testing Paradigm Generates In Vivo Animal Data for all Possible Outcomes to Determine which of all Possible Effects are Relevant BATTERY of Animal Testing (Part 158) 10 Implementing Change • Development and implementation of a new, integrated approach to the testing and assessment of pesticides will be a challenge and will take place over the next 10 years • Scientific tools and knowledge must be advanced and public understanding and confidence must be developed • National Academy of Science study

EPA-Pesticide Program Plan for Paradigm Change Analyze and Update Current Data Requirements sed Changes to Regulations on Testing ayei aafor Key Support Development and Use of Enhanced and New Testing Approaches and other Analytic Techniques ILSI/HESI Proposed Tiered Approach Inert Ingredient SAR Analysis Advance Research Agenda -Greater Reliance on Emerging Tools of Computational Toxicology Retrospective Analyses of Pesticide Database ·Ongoing Reviews -Dog Toxicity Studies -Rodent Cancer Studies -Rat Multi-generation Reproductive Studies -Rat Neurodevelopmental Toxicity Studies Incorporate Lessons Learned into Regulatory Practice

6 11 EPA – Pesticide Program Plan for Paradigm Change • Analyze and Update Current Data Requirements – Proposed Changes to Regulations on Testing Requirement – Retrospective Analyses of Pesticide Data for Key Endpoints • Support Development and Use of Enhanced and New Testing Approaches and other Analytic Techniques – ILSI/HESI Proposed Tiered Approach – Inert Ingredient SAR Analysis • Advance Research Agenda – Greater Reliance on Emerging Tools of Computational Toxicology 12 Retrospective Analyses of Pesticide Database • Ongoing Reviews – Dog Toxicity Studies – Rodent Cancer Studies – Rat Multi-generation Reproductive Studies – Rat Neurodevelopmental Toxicity Studies • Incorporate Lessons Learned into Regulatory Practice

le Org Appropriate Dose Metric Enhanced and New Testing Approaches ·Short Term Goal -Make existing animal testing paradigm more efficient, reliable&responsive to our rrisk assessment management needs FQPA Issues(lifestage susceptibilites,mechanisms of toxicity, ILSI-HESI Proposed Tiered Approach -Important Springboard .Reduces animal usage by optimizing study designs takes risk assessment needs&exposure characteristics into account More Foundation Consensus Building Needed Retrospective prospective analyses 7

7 13 Appropriate Dose Metric Response Endpoint Subcellular Cell Tissue Chronic Whole Organism Acute Whole Organism 14 • Short Term Goal – Make existing animal testing paradigm more efficient, reliable & responsive to our risk assessment & management needs • FQPA Issues (lifestage susceptibilites, mechanisms of toxicity, etc) • ILSI-HESI Proposed Tiered Approach – Important Springboard • Reduces animal usage by optimizing study designs & takes risk assessment needs & exposure characteristics into account – More Foundation & Consensus Building Needed • Retrospective & prospective analyses Enhanced and New Testing Approaches

The New Hypothesis-Driven Paradigm Pesticide Inventories Molecular interactions Biochemical Responses Cellular Responses Tissue/Organ Function erse Outcomes al Deficits Example:Receptor-Mediated Pathways Linkage Across Levels of Biological Organization Molecular Cellular Optimizing Resources,Costs,and Time in Generating and Evaluating Informatior Understanding Relevance

8 15 Mortality •Systemic Toxicity •Disease •Cancer Developmental Impairment •Terato •Prenatal Deficits Reproductive Fitness •Viable Offspring •Fertility Molecular Interactions Biochemical Responses Cellular Responses Tissue/Organ Function Pesticide Inventories C2Cl3 Cl C Cl C2Cl3 Cl C Cl C2Cl3 Cl C Cl Cl Cl Cl Cl Cl Cl Cl C l Cl Cl C l Cl Cl Cl Cl Cl Cl Cl C l Cl Cl C l Cl Cl OH OH OH The New Hypothesis-Driven Paradigm Existing data; In silico and In vitro Prioritization; Screening Adverse Outcomes Efficient, Focused In vivo Animal Testing 16 Chemical 2-D Structure/ Properties Chemical 3-D Structure/ Properties Receptor/Ligand Interaction -Gene Activation -Protein Production -Gonad Development -Altered Hormone Levels Impaired Reproduction Linkage Across Levels of Biological Organization Molecular Cellular Organ Individual Understanding Relevance Example: Receptor-Mediated Pathways Optimizing Resources, Costs, and Time in Generating and Evaluating Information

A New Toxicology Testing Paradigm:Meeting Common Needs Toxicity Pathway silco-QSAR Direct Chemical Bir ng to An gen Receptor Js Area In vivo Assays (enobiotic CELLULAR TISSUE/ORGAN POPULATION AR Binding xpression Risk Assessment Relevance The New Hypothesis-Driven Paradigm Example:Receptor-Mediated Pathway Pesticide Inventories Molecular Interactions Gene Response Protein Expression Adverse Outcomes

9 17 In silico - QSAR Focus Area Xenobiotic AR Binding Altered Gene Expression Chg Hormone Levels, Testis Altered Repro. Function Toxicological Understanding Risk Assessment Relevance In vivo Assays In vitro Focus Area MOLECULAR CELLULAR TISSUE/ORGAN INDIVIDUAL Infertility POPULATION Toxicity Pathway Direct Chemical Binding to Androgen Receptor A New Toxicology Testing Paradigm: Meeting Common Needs 18 Reproductive Fitness •Viable Offspring •Fertility Molecular Interactions Gene Response Protein Expression Pesticide Inventories C2Cl3 Cl C Cl C2Cl3 Cl C Cl C2Cl3 Cl C Cl Cl Cl Cl Cl Cl Cl Cl C l Cl Cl C l Cl Cl Cl Cl Cl Cl Cl C l Cl Cl C l Cl Cl OH OH OH The New Hypothesis-Driven Paradigm Existing data, In silico , In vitro & Prioritization; Screening Example: Receptor-Mediated Pathway Efficient, Focused Adverse Outcomes Animal Testing

Next Steps Work with the regulated community and other stakeholders 。 Support the development and use of enhanced and new testing approaches and other analytic techniques Incorporate lessons learned into regulatory practice on a case-by-case basis. Ultimately,explore and make appropriate changes to regulations and test guidelines Coordination and Alignment Coordinate EPA's regulatory and research programs (OPPTS/ORD-computational toxicology program) Partner with other Federal Agencies(e.g.,FDA,NIEHS) Partner with regulatory and research agencies in other countries (.e.g.,Canada,Australia,EU Member States) through existing international fora(e.g.,NAFTA,OECD WHO) Work with scientific community and other stakeholders (ILSI/HESI,Federal Advisory Committees,NAS) 10

10 19 Next Steps • Work with the regulated community and other stakeholders • Support the development and use of enhanced and new testing approaches and other analytic techniques • Incorporate lessons learned into regulatory practice on a case-by-case basis. • Ultimately, explore and make appropriate changes to regulations and test guidelines 20 • Coordinate EPA’s regulatory and research programs (OPPTS/ORD – computational toxicology program) • Partner with other Federal Agencies (e.g., FDA, NIEHS) • Partner with regulatory and research agencies in other countries (.e.g., Canada, Australia, EU Member States) through existing international fora (e.g., NAFTA, OECD, WHO) • Work with scientific community and other stakeholders (ILSI/HESI, Federal Advisory Committees, NAS) Coordination and Alignment