An Overview of Risk Assessment

1. An Overview of Risk Assessment Bernard D. Goldstein, MD University of Pittsburgh Graduate School of Public Health

2. An Overview of Risk AssessmentObjectives of this Lecture • The student will have an understanding of: • The definition of risk assessment and its four components, including their scientific basis. • The basic issues in environmental policy that are responsible for the genesis and use of risk assessment. • The key strengths and weaknesses of risk assessment as a public policy tool • The role of risk assessment as an interface between environmental science and public policy

3. What Are the Components of Risk Assessment? • Hazard identification • Dose-response evaluation • Human exposure evaluation • Risk characterization

4. Better Things Through Chemistry 5,000,000 known chemicals (1,000,000 in 1945) 70,000 chemicals in widespread use 1,500 new chemicals in use yearly Annual bioassay capability about 500/year

5. Scientists manipulate formulae to match the real world. Policymakers manipulate the real world to match formulae.

6. Comparative Risk of Death

7. Research and Data Collection Risk Assessment Risk Management

8. The Three Laws of Toxicology • The dose makes the poison • Chemicals have specific effects • Humans are animals

9. Hazard Identification The determination of whether a particular chemical or agent is or is not causally linked to a particular health effect.

10. IARC Overall Evaluation of Carcinogenicity to Humans 1 Carcinogenic to Humans 2A Probably Carcinogenic 2B Possibly Carcinogenic 3 Not Classifiable 4 Probably Not Carcinogenic Weight of Evidence

11. Dose Response Evaluation The determination of the relation between the magnitude of exposure and the probability of occurrence of the health effect in question.

12. Dose-Response Curve Observable Range Response Range of Inference Dose

13. Structure of DNA

14. Human Exposure Evaluation • How many people will be exposed? • Through which routes? • Who is exposed? • What is the magnitude, duration, and timing of the exposure?

15. Continuum for the Emission of and Exposure to a Contaminant and the Expression of a Health Effect Accumulation Human Potential Dose Source Transport and in Contact Emission Transformation to the Body Environment Exposure Early Biologically Health Effect Expression of Internal Dose Effective Dose Disease Elimination Accumulation Bioavailability Transformation P.J. Lioy, Env. Sci. & Tech. Submitted 1990

16. Risk Characterization The description of the nature and often the magnitude of the human risk, including attendant uncertainty.

17. Risk Assessment Dose-Response Assessment Hazard Identification Risk Characterization Exposure Assessment

18. Risk Assessment Risk Management Dose-Response Assessment Regulatory Decision Risk Characterization Hazard Identification Control Options Exposure Assessment Non-Risk Analysis

19. The Three Laws of Toxicology • The dose makes the poison • Chemicals have specific effects • Humans are animals

20. Uses of Risk Assessment for Management Decision Making • National Regulations: • Environmental standards (air, water, hazardous waste, etc.) • Food safety (chemical contaminants, additives, pathogens) • Manufacturing and production (pharmaceuticals, pesticides, etc.) • International Trade / WTO SPS Agreement: • Food products (Safety Assessment and Acceptable Daily Intake [ADI]) • Animals and animal products • Plants and plant products

21. X X X X X X Range of Expert Judgment

22. X X X X X X Range of Expert Judgment

23. Communication of Science

24. In the presence of uncertainty, the technique usually relied upon to ascertain the current state of knowledge is: CONSENSUS by SCIENTISTS BALANCE by JOURNALISTS CONFRONTATION by LAWYERS

25. CATNIP PRINCIPLE Cheapest Available Technology Not Involving Prosecution

26. Margin of Safety Is it Risk Assessment or Risk Management? Components of decision: What is strength of positive data? What is strength of negative data? Is uncertainty qualitative or quantitative? What is the clinical significance of risk?

27. Problems and Limitations of Risk Assessment 1. The process by which policy and science are mixed together in a risk assessment is poorly understood. 2. Its ability to provide a “Bright Line” has been overstated by risk assessors and overused by regulators and lawmakers.

28. Problems and Limitations of Risk Assessment(continued) 3. The data quality objective for the different goals and types of risk assessment is poorly understood. 4. There is often a substantial gap between the data quality objective of the decision maker and the degree of complexity of the assessment, with unnecessary analyses confusing and delaying response.

29. Problems and Limitations of Risk Assessment(continued) 5. Risk assessment often obscures the substantial gap between the data needs for good public health decision making and the paucity of available data. 6. Risk characterization should be extended beyond a probabilistic statement of cancer risk to include considerations of other health and non-health endpoints.

30. Problems and Limitations of Risk Assessment(continued) 7. Risk assessment is secondary prevention rather than primary prevention.

31. Risk Assessment and Risk Management is a 3 Step Process • Science Policy producing Risk Assessment Guidelines • Risk Assessment • Risk Management

32. Risk Assessment Guidelines:Use and Intent • Provide consistency • Establish data quality objectives • Assure technical quality • Clarify scientific assumptions • Allow flexibility to be transparent • Provide public with “Road Map”

33. Precautionary Principle Described in the Rio Declaration: Nations shall use the precautionary approach to protect the environment. Where there are threats of serious or irreversible damage, scientific uncertainty shall not be used to postpone cost-effective measures to prevent environmental degradation.

34. Definition of the Precautionary Principle (Cynical Version) The Precautionary Principle is a nebulous doctrine developed by Europeans as a means to erect a trade barrier against any item that can be produced more efficiently elsewhere

35. RISK ASSESSMENT AND THE PRECAUTIONARY PRINCIPLEThree different views • The Precautionary Principle is already incorporated in Risk Assessment • The Precautionary Principle should be incorporated into Risk Assessment • The Precautionary Principle and Risk Assessment are completely antithetical

37. Framework is Conducted: • In collaborationwith stakeholders. • Usingiterations if new information is developed that changes the need for or nature of risk management.