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An Introduction to the Principles of Toxicology

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  1. An Introduction to the Principles of Toxicology A Small Dose of Toxicology ENV H 472 A - ENVIRONMENTAL RISK AND SOCIETY Class 2 Steven G. Gilbert, PhD, DABT

  2. A Small Dose of Toxicology See: -- smdose

  3. Small Dose of Toxicology

  4. Milestones of Toxicology

  5. 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

  6. The World Library of Toxicology

  7. Toxipediasuite of sites

  8. 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

  9. LDDI Consensus Statement Given the established knowledge, protecting children from neurotoxic environmental exposures from the earliest stages of fetal development clearly is an essential public health measure if we are to help prevent learning and developmental disorders and create an environment in which children can reach and maintain their full potential.

  10. NW Public Health Public Health and the Precautionary Principle By Steven G. Gilbert See: nwph

  11. 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.

  12. 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)

  13. Child Health

  14. 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

  15. 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

  16. 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 ----------

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

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

  19. 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

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

  21. Toxicology Definitions The study of poisons or the adverse effects of chemical and physical agents on living organisms.

  22. Ancient Awareness 399 BC Death of Socrates by Hemlock Socrates was charged with religious heresy and corrupting the morals of local youth. The active chemical used was the alkaloid coniine which, when ingested causes paralysis, convulsions and potentially death.

  23. Historical Awareness From Romeo and Juliet - act 5 Come bitter pilot, now at once run on The dashing rocks thy seasick weary bark! Here’s to my love! O true apothecary! Thy drugs are quick. Thus with a kiss I die. Shakespeare (1564-1616)

  24. Human & Environmental Health “Conditions that ensure that all living things have the best opportunity to reach and maintain their full genetic potential.” Steven G. Gilbert, 1999

  25. What do these have in common? • Hong Kong • Princess Diana • Ambassador to Mexico • Coeur d’Alene, Silver Valley, ID • Tacoma • $100 Billion, $65 Billion • Food, noise, dust • 11,000 to 689,000 Children

  26. Who are these white guys?

  27. Power To Discover The Truth “It is not the truth that makes you free. It is your possession of the power to discover the truth. Our dilemma is that we do not know how to provide that power.” Richard Lewontin (New York Review of Books, Jan 7, 1997)

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

  29. Risk = Hazard X Exposure Key Words Dose / Response Individual Sensitivity

  30. Paracelsus “All substances are poisons; there is none which is not a poison. The right dose differentiates a poison from a remedy.” Paracelsus (1493-1541)

  31. An Individual View “The sensitivity of the individual differentiates a poison from a remedy. The fundamental principle of toxicology is the individual’s response to a dose.” S. G. Gilbert (1997)

  32. Superman

  33. Neuron

  34. Thalidomide • Introduced in 1956 as sedative (sleeping pill) and to reduce nausea and vomiting during pregnancy • Withdrawn in 1961 • Discovered to be a human teratogen causing absence of limbs or limb malformations in newborns • 5000 to 7000 infants effected • Resulted in new drug testing rules

  35. H H C C OH H H H What Is This? (CH3-CH2-OH)

  36. Effects of Prenatal Alcohol

  37. FAS Child

  38. Mouse – Scanning EM

  39. A Small Dose of Lead

  40. Lead In Homes

  41. Greek 2nd BC Lead History Lead Makes the Mind Give Way

  42. Recycling Lead

  43. Agency Blood Lead Levels

  44. A Small Dose of Mercury

  45. Hg – Like Water

  46. Polluting with HG Discharge in Minamata Bay

  47. Fetal Effects of MeHg

  48. Life-Long Effects of MeHg

  49. The Mercury Cycle

  50. Pesticide Application