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Precautionary Assessment

Precautionary Assessment. “Precautionary Assessment"-- a community approach to risk assessment (Critical Analysis of Risk Assessment & Alternative Approaches). Northwest Toxic Communities Coalition April 5,, 2009. Steven G. Gilbert, PhD, DABT www.asmalldoseof.org www.toxipedia.org.

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Precautionary Assessment

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  1. Precautionary Assessment “Precautionary Assessment"-- a community approach to risk assessment(Critical Analysis of Risk Assessment & Alternative Approaches) Northwest Toxic Communities CoalitionApril 5,, 2009 Steven G. Gilbert, PhD, DABT www.asmalldoseof.org www.toxipedia.org

  2. Doubt Is Their Product How Industry’s Assault on Science Threatens Your Health” David Michaels 2008 - Oxford

  3. A Small Dose of Toxicology See: www.asmalldoseof.org -- smdose

  4. Small Dose of Toxicology

  5. Milestones of Toxicology

  6. www.toxipedia.org A free toxicology encyclopedia and resource center that anyone can edit. Toxipedia provides comprehensive, accurate, and scientifically based information on the hazards and risks of chemical and physical agents, with the goal of advancing human and environmental health. Toxipedia

  7. www.ipmopedia.org

  8. Healthy World Theater Coupling art and science to forge a more healthy and peaceful world Healthy World Theater reaches to the heart to promote awareness and understanding through the arts to create a more healthy and peaceful world so that all creatures may reach, maintain, and enjoy their potential. www.healthyworldtheater.org

  9. World Library of Toxicology – www.wltox.org

  10. LDDI Consensus Statement Scientific Consensus Statement on Environmental Agents Associated with Neurodevelopmental Disorders Developed by the Collaborative on Health and the Environment’s Learning and Developmental Disabilities Initiative November 7, 2007 http://www.iceh.org/LDDI.html

  11. Child Health

  12. So Many Chemicals so Little Data 2863 above 1 Million pounds 12 or 0.4% good data 21.4% some data 78.2% no data www.preventingharm.org

  13. The Consequences • Nearly 12 million children (17%) under age 18 in the US suffer from one or more developmental disabilities • Learning disabilities – 5-10% of kids in public school • ADHD – 3-6% of all school kids, maybe higher

  14. Risk Assessment "We should remember that risk assessment data can be like the captured spy: If you torture it long enough, it will tell you anything you want to know." (William Ruckelshaus -1st administrator of U.S. EPA 1984.)

  15. Risk Assessment Philip Handler said about balancing risks and benefits: “A sensible guide would surely be to reduce exposure to hazard whenever possible, to accept substantial hazard only for great benefit, minor hazard for modest benefit, and no hazard at all when the benefit seems relatively trivial.” (Handler, 1979). Handler P. 1979. Some comments on risk. In: The National Research Council in 1979; Current Issues and Studies. Washington, DC: National Academy of Sciences, 3-24.

  16. Outline Risk Assessment – Arbitrary and Capricious • Vision and Ethics • Principles of Risk Assessment • Risk Assessment - examples • Weaknesses of Risk Assessment • Beyond Risk Assessment to Precautionary Assessment

  17. Vision for Child Health “Children can develop and mature in an environment that allows them to reach and maintain their full potential.”

  18. Human & Environmental Health “Conditions that ensure that all living things have the best opportunity to reach and maintain their full genetic potential.” S. Gilbert (1999)

  19. Socially responsible white guys?

  20. The First Bioethicist Aldo Leopold "A thing is right when it tends to preserve the integrity, stability, and beauty of the biotic community. It is wrong when it tends otherwise." - Aldo Leopold, 1949, A Sand County Almanac ---------- 1887 - 1948 ----------

  21. Limits on Freedom “An ethic, ecologically, is a limitation on freedom of action in the struggle for existence” Aldo Leopold

  22. “The Commons” The Tragedy of the Commons By Garrett Hardin, Science, 1968

  23. Technical Solutions “It is our considered professional judgment that this dilemma has no technical solution.” The Tragedy of the Commons By Garrett Hardin, Science, 1968

  24. Problems – Solutions? • Lead and kids • Fetal alcohol syndrome • Nuclear disarmament • Bioterrorism • Ocean Fisheries • Persistent chemicals • The Commons

  25. Sir Austin Bradford Hill "All scientific work is incomplete - whether it be observational or experimental. All scientific work is liable to be upset or modified by advancing knowledge. That does not confer upon us a freedom to ignore the knowledge we already have or postpone the action that it appears to demand at a given time. " Sir Austin Bradford Hill (1965)

  26. Determining Causation • Strength of association • Consistency of findings • Biological gradient • Temporal sequence • Biologic or theoretical plausibility • Coherence with established knowledge • Specificity of association • Sir Austin Bradford Hill (1965)

  27. Precautionary Principle “When an activity raises threats of harm to human health or the environment, precautionary measures should be take even if some cause and effect relationships are not fully established scientifically.” Wingspread Conference, 1998.

  28. Central components • Setting goals (Health indicators) • Taking preventive action in the face of uncertainty • Shifting the burden of responsibility to the proponents of an activity (Who benefits?) • Exploring a wide range of alternatives to possibly harmful actions (Is it necessary?) • Increasing public participation in decision making (transparency of information & environmental justice)

  29. Hazard X Exposure = Risk Key Words of Toxicology Dose / Response Individual Susceptibility

  30. Modern Risk Assessment • Developed in 1960-1970s • Concern over increased cancer rates • Expanded to non-cancer effects

  31. Perspective "If someone had evaluated the risk of fire right after it was invented, they may well have decided to eat their food raw." Julian Morris of the Institute of Economic Affairs in London

  32. Quantitative Risk Assessment Process of estimating association between an exposure to a chemical or physical agent and the incidence of some adverse outcome. National Research Council, Risk Assessment in the Federal Government: Managing the Process. National Academy Press, Washington, DC, 1983

  33. Steps in Risk Assessment • Hazard Identification • Exposure Assessment • Dose-Response Assessment • Risk Characterization

  34. What Hazard? • Obvious • Death, Cancer, Acid burn, Birth defect, asthma ….. • Subtle • Decreases in learning and memory (lead) • Loss of potential • Sensitivity of the individual (child)

  35. Hazard Identification Review human and animal data to determine if a chemical or agent has biological effects.

  36. Toxicity Endpoints • Carcinogenicity • Mutations • Altered immune function • Teratogenicity • Altered reproductive function • Neuro-behavioral toxicity • Organ-specific effects • Ecological effects (wildlife, environmental persistence)

  37. Exposure Assessment • Route of exposure (skin, oral, inhalation) • Amount of exposure (dose) • Duration of exposure • To whom (animals, humans, environment) • Children, other sensitive individuals

  38. Exposure Issues • Home environment • Workplace (occupational) • School • Food • Consumer products • Global and local environment

  39. Dose-Response Assessment How much exposure to a chemical or agent will cause what effect? Dose – Response

  40. Some Jargon LOAEL – Lowest Observed Adverse Effect Level (mg/kg) NOAEL – No Observed Adverse Effect Level (mg/kg) RfD – Reference Dose (mg/kg-day)

  41. Greater Dose – Greater Response ED50 Response Threshold (NOAEL) LOAEL Dose

  42. Hazard (including sensitive populations) Low dose extrapolation Exposure Route of exposure, amount, duration dermal, oral, inhalation, injection To Whom? Sensitive Individuals? Risk Characterization Risk = Hazard X Exposure

  43. Use of Uncertainty Factors • Divide Dose by Power of 10 • Human variability • Interspecies extrapolation • Children • Subchronic to chronic extrapolation • Absence of a NOAEL • Database uncertainty

  44. Human Variability • Human Subject Variability • Lifestyle – risk of exposure to …. • Occupation – risk of exposure to …. • Breathing & digestion – uptake of chemicals • Metabolism & kidney function – elimination • Age, gender & disease – susceptibility to toxicity • Socio/economic facts

  45. Doubt / Uncertainty "Doubt is our product since it is the best means of competing with the 'body of fact' that exists in the mind of the general public.“ 1969 an executive at Brown & Williamson owned by R. J. Reynolds Tobacco Company (Doubt Is Their Product by David Michaels in Scientific American, June 15, 2005)

  46. Use of Uncertainty Factors Animal Dose Response Data NOAEL (No Observed Adverse Effect Level) or LOAEL Divide by 10 (Account for inadequate animal data) Divide by 10 (Animal to Human Extrapolation) Divide by 10 (Human Variability or Individual Sensitivity) Reference Dose (RfD) Or Acceptable Daily Intake (ADI)

  47. What Is This? O CH3 CH3 N N 7 1 3 O N N CH3

  48. Mercury & Toxicology

  49. The Mercury Cycle

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