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The past, present and future of childhood lead poisoning

The past, present and future of childhood lead poisoning. Two Thousand Years of Lead Poisoning 1st Century AD. Dioscerides: Lead makes the mind give way 1763. Benjamin Franklin:Lead in painters, printers and tinkers 1830 Charles Dickens: Uncommercial Traveler

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The past, present and future of childhood lead poisoning

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  1. The past, present and future of childhood lead poisoning

  2. Two Thousand Years of Lead Poisoning • 1st Century AD. Dioscerides: Lead makes the mind give way • 1763. Benjamin Franklin:Lead in painters, printers and tinkers • 1830 Charles Dickens: Uncommercial Traveler • 1892. Brisbane Australia: Childhood lead poisoning described • 1943. Randolph Byers: Long term effects • 1991. PHS Strategic Plan • 1993: NAS Report

  3. Five Phases of Lead Toxicology • There is no such thing as childhood lead poisoning. (1892)

  4. J Lockhart Gibson Gibson

  5. Five Phases of Lead Toxicology • It exists, but if it doesn’t kill you, it doesn’t touch you (1943)

  6. Byers Byers

  7. Five Phases of Lead Toxicology • There are long term effects, but only in children with severe symptoms (1979) • Silent lead exposure has long term consequences • Lead exposure is associated with antisocial behavior

  8. Flaws in Early Studies • Inadequate exposure markers • Screening or group measures of outcome • Inadequate control of confounders • Potential selection bias

  9. Responses to Design Issues • Replaced blood with dentine • Tested 3500 teeth from 2500 subjects in primary school • Measured 40 covariates; adjusted for those that were associated with exposure

  10. Neuropsychological Effects of Lead

  11. Classroom PerformanceTeacher’s Ratings

  12. The Effects of Lead Are Permanent

  13. The Effects of Lead are Permanent

  14. Prenatal Lead Exposure

  15. Newer Studies • Lanphear et al.Cognitive deficits associated with blood lead concentrations <10 microg/dL in US children and adolescents.Public Health Rep. 2000 • Canfield et al Intellectual impairment in children with blood lead concentrations below 10 microg per deciliter.NEJM 2003 • Bellinger and Needleman Intellectual impairment and blood lead levels NEJM 2003

  16. Slope of Lead/IQ Regression

  17. Most of the IQ Loss Takes Place at the Lower Dose

  18. Chiodo et al NTT 2004

  19. Clues to the Lead/Delinquency link Race Urban residence Low IQ ADHD Moffit’s studies

  20. Case-Control Study • 195 adjudicated delinquents, 155 controls • Bone lead levels • Cases 11ppm±32ppm • Controls 1.5 ± 32ppm • 10 variates controlled in the analysis • Odds ratio 4.0 ( 1.4-11.1) • Population attributable risk: 11%-38%

  21. Sales of Leaded Gasoline and Murder Rates

  22. Robbery and Lead Sales

  23. The Nature of Aging • A reduction in molecular fidelity over time exceeding the organism’s repair capability • Due to the inherent thermodynamic instability of complex molecules

  24. Processes Associated with the Aging Process • DNA mutations • ROS damage • Mitochondrial damage • Shortening of telomeres

  25. Toxic Expressions of Lead • Mutations: Klug’s findings • Mitochondrial damage • ALAD and mitochondria • Heme deficiency and neuronal decay

  26. Lead and t RNA

  27. Lead and Telomerase • Sheng Wu Hua Xue Yu Sheng WU Wu Li Xue Bao( Shanghai) 2002 34: 240-4

  28. Risk factors Common to Alzheimer’s and Lead • Race • Urbanization • Autopsy findings: Niklowitz • Apoptosis • Fetal exposure and later disease

  29. Changes in APP and -actin RNA

  30. Good Public Health Policy Pays Off

  31. Doing Well by Doing Good

  32. Reasons for Persistence of Lead Poisoning • Belief that it is a poor black problem • Belief that it is a problem of poor child rearing • Belief that the problem has been solved • Lack of interest by academic pediatrics • Efforts of lead industry to disguise the problem • Belief that we cannot afford to solve the problem

  33. When a thing was new, people said: • “It’s not true.” • When it was shown to be true, people said: • “It’s not important.” • And when its importance could no longer be denied, people said:“Anyway, it’s not new.” • William James

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