Risk Management: A Conceptual Introduction

1. Risk Management: A Conceptual Introduction Tee L. Guidotti Occupational Health Program University of Alberta

2. Dimensions of Risk Management • Risk perception • Risk communication • Risk control • structural change • reduce exposure • reduce potential loss or liability • Risk anticipation • Risk comparison

3. What is Risk - Really? • A conceptual abstraction - “risk” does not exist per se • Risk is a description of the behaviour of a system, either in past or predicted • Risk reflects characteristics of the system, subject to change • Risk is fundamental to change or adaptation • All society is about mitigating risk

4. Legal standard of certainty Allowable scientific error Clinical complications Public health (e.g. vaccine safety) De minimis 0.5 0.05 (p value) 0.01 - 0.1 10-5 - 10-4 10-5 Levels of Risk

5. Risk Perception

6. Risk Perception • Public view of risk may not match that of experts • People tend to estimate risk best in the middle of the range - they distort the extremes • Risk perception is laden with values learned in society and the family • Risk perception is culturally determined • Risk is perceived as good in many contexts

7. Risk Communication

8. Cardinal Rules for Risk Communication • Accept, involve public as legitimate partner • Plan carefully and evaluate performance • Listen to the audience • Be honest, frank and open • Coordinate, collaborate with other credible sources • Meet the needs of the media • Speak clearly and with compassion After Covello; originally prepared for U.S. EPA.

9. Risk control • structural change • engineering and environmental change • replacement • reduce exposure • protection • isolation • reduce potential loss (mitigate effects) • reduce potential liability

10. Achieving Risk Control • Market incentives • Regulation • Voluntary compliance • may involve mutual coercion • role of guidelines • indirect regulation • Cultural norms

11. Risk Control through Regulation

12. Regulatory Options

13. Standards Legal authority usually delegated Binding Mandatory compliance Enforceable Universal application Consultation process Guidelines Authority usually negotiated Advisory Voluntary compliance No sanctions Discretionary Multistakeholder process Standards v. Guidelines

14. Examples of Standards - US

15. Examples of Guidelines - US

16. Standards and Guidelines in Canada

17. Establishing Exposure Standards • Occupational v. environmental (assumptions of vulnerability) • General benchmark required • risk based • non-degradation (historical) • reference level,  NOAEL/safety factor • technology-driven • Appropriate model for extrapolation

18. How Standards Are Set - U.S. EPA as an Example

19. Two Models for Standard Setting • Noncarcinogens (direct effects model) • Carcinogens (stochastic model) These standards-setting models flow logically from the risk assessment models used for each.

20. Model: Non-Carcinogens • Standards for non-carcinogens typically assume a toxicologic exposure-response relationship • based on known exposure-response slope • identify NOAEL, extrapolate to humans • safety factors (uncertainty factors) • Acceptable risk is below chronic toxicity level for most vulnerable subgroups

21. RfD = NOAEL/(UF1 … Ufn)

22. Safety Factors (US EPA)

23. Model for Carcinogens • Stochastic model, derive maximum likelihood estimate or UCL of frequency-response slope • Derive unit cancer risk, q1* • Individual lifetime cancer risk = exposure  slope • Adjust allowable exposure to de minimis risk level ( 10–5)

24. Implications of Model for Carcinogens • Because risk level is preset, little flexibility • Safety factors do not apply • Low-dose extrapolation: on-going debate • Tends to drive standards-setting in mixtures of carcinogenic, non-carcinogenic agents • benzene in Cdn drinking water guidelines • benzene drives BTEX-based evaluations • PAHs drive CCME guidelines

25. Historical Derivation of Standards • Consensual process or majority of an authoritative group • Based on review of the evidence • Considerable debate in camera • Issues of role and conflict of interest • Problem of disinterested expert • Disillusionment and opening of process

26. Risk Anticipation • New idea, in evolution • Anticipate risk before it becomes a management problem • Requires internal culture of skepticism

27. Risk Comparison • A systematic process of consultation in an open, multistakeholder process • expert panels • public(s) • Iterative process in open discussion • Consensus on magnitude of risks • Consensus on priorities and ranking of risks

28. Benefits Consensus, once achieved, is solid Broadly inclusive Educates constituencies Direct guidance for public priorities, e.g. budgets Provides framework for NGO participation Drawbacks Very time consuming Easily hijacked Requires active outreach to constituencies NGOs may lead public NGOs may not be representative of public opinion Risk Comparison