Everything You Always Wanted to Know About Childhood Lead Poisoning (but Were Afraid to Ask)

1. Everything You Always Wanted to Know About Childhood Lead Poisoning (but Were Afraid to Ask) June 21, 2007 Steven Rosenberg, M.D., M.P.H. Public HealthMedical OfficerChildhood Lead Poisoning Prevention BranchCalifornia Department of Health Services

2. “Why should I screen?” “What difference does it make anyway?” “ Is it going to take up too much time?”

3. Objectives • Toxicology of lead • Sources and risks • Effects of lead at low levels • Screening requirements • Illustration with a case study • Case management

4. The Basics of Lead • Whole blood in micrograms per deciliter • Venous blood sample is gold standard • CDC level of concern >/= 10 mcg/dL * • Most children BLL <2mcg/dL • No known safe levels • IQ Effects below “Level of Concern” ** *MMWR 5/27/2005 ** Confirmed by meta-analysis by Koller et al. EHP, Jun 2004

5. Metabolism of Lead • Main absorption in children is gastrointestinal • Similar to iron & calcium • 70% total body lead is stored in bone* • Half-life in blood is weeks • Half-life in bone is decades *Environmental Health Perspectives 1993, 101:598-616

6. Health Effects of Lead • Sub-clinical • Iron deficiency associated with elevated blood lead level * • Interferes with hemoglobin synthesis • Free erythrocyte protoporphyrin • Basophillic stippling • Neuro-developmental toxin * Wright, et al, J Pediatr, 2003; 142: 9-14

7. Prolonged IQ Effects • After early childhood exposure • IQ can drop 5-8 points • Multiple studies • Even at levels < 10 mcg/dL Bellinger, 1992, decrease of 5.8 IQ points Pocock & Smith, 1994, Review Needleman, 2004, Lead Poisoning

8. Graph Illustrating Inverse Relationship Between IQ and Lead Level 125 WISC-R Full-scale IQ K-TEA Battery Composite 120 Adjusted Intelligence Test Score at Age 10 115 110 105 0 0-4.9 5.0-9.9 10.0-14.9 ≥15.0 Blood Lead Level at 24 Months of Age (µg/dL) Source: Bellinger, et al. Pediatrics (1992)

9. “What’s the impact of an average drop of 5 IQ points?”

10. 80 40 60 100 120 140 160 70 130 Effects of a Small Shift in IQ Distribution in a Population of 260 Million Normal: mean = 100 6.0 million 6.0 million "gifted" “special health & educational needs" I.Q. Adapted from Pediatric Environmental Toolkit

11. 40 80 100 120 140 160 60 70 130 5 Point Decrease in Mean IQ Mean 95 57% DECREASE 9.4 million 2.4 million “special health & educational needs" "gifted" 57% INCREASE I.Q. Adapted from Pediatric Environmental Toolkit

12. In economic terms: Value of one IQ point (in year 2000 dollars) = ~$15,000 Economic savings to society for the decrease of lead in US population from 17.1ug/dL to 2ug/dL = $319 billion Grosse et al, Environmental Health Perspectives, June 2002, 110:563-569 Rothenberg & Rothenberg, Environmental Health Perspectives, Sept 2005, 113: 1190-1195

13. Studies Correlate Lead in Childhood With: • Poor academic achievement 1 • Juvenile delinquency 2 • Elevated school drop-out rate 3 • Direct effect on behavior 4 • ADHD 5 • Even at low levels 6 1. Bellinger DC, et al. Pediatrics 1992; 90(6):855-61 2. Dietrich KN, et al. Neurotoxicol Teratol 2001; 23(6):511-8 Needleman HL, et al. Neurotoxicol Teratol 2002; 24(6):711-7 3. Needleman, et al. NEJM 1990; 322(2):83-8 4. Chen, et al. Pediatrics 2007; 119:e650-8 5. Braun, et al. Environ Health Perspect 2006; 114:1904-9 6. Canfield et al. NEJM 2003; 348(16):1517-26

14. How much lead is hazardous? • 1 gram packet of lead dust spread over 10,000 ft2 gives lead level of 100 μg/ft2 • Current EPA acceptable level: 40 μg/ft2 • FDA recommended maximum consumption: 6 μg per day “LEAD DUST”

15. What are the common sources of lead?

18. 4 3.5 3 2.5 2 1.5 1 0.5 0 NY PA CA IL OH MI MA NJ TX WI Top Ten States Top Ten States with pre-1950 Housing Number of pre-1950 Housing Units (in millions)

21. Change in Blood Lead Levels in Relation to Decline in Use of Leaded Gasoline 1976-1980 Source: Annest JL, 1983

22. Lead in soil remains

23. What are other, less common, sources of lead?

24. Occupational Sources Brought Home • Storage battery manufacture/repair/recycling • Painting/soldering/remodeling • Heavy construction/abatement • Smelting/brass/bronze working • Firing ranges/metal work

25. At Risk Hobbies • Stained Glass Making • Furniture Painting/Refinishing • Ceramic Glazing • Soldering Jewelry • Lead fishing weights • Firearms • Collectibles

26. Imported Ceramics CAZUELA Lead-Glazed Stoneware

27. JARRA Eating Dirt: ww.cdc.gov/ncidod/eid/vol9no8/pdfs/03-0033.pdf

28. Lead in Imported Candy* *& other foods & spices

29. Lead in Imported Jewelry

30. Lead in Folk Remedies Ayruvedicmedications Sindoor Pay-loo-ah

31. Who is at risk? • Toddlers 1-2 years old • Hand mouth behavior • Pica • Government-assisted programs: • Medi-Cal • CHDP* • WIC** • Healthy families *Child Health & Disability Prevention Program **Woman & Infant Care program

32. Prevalence of EBL by Funding Source BLL≥ 10 mcg/dL insurance Source: US GAO Report 1999, NHANES III, Phase 2, data early 1990’s

33. Why aren’t high-risk kids being screened? • Not ordered by physician • Families don’t go to get blood drawn • High-risk kids aren’t getting well child visits

34. “Maybe my population is not at-risk — at what incidence should a disease occur before it is worthwhile to screen?”

35. Incidence of Screened Inborn Errors of Metabolism 1:3,000 1:12,000 1:25,000 ≥

36. Childhood Lead Poisoning Prevention Program: • ~600,000 children received blood lead testing in 2006 • Average BLL < 2 mcg/dL • 0.7% had results reflecting CDC level of concern

37. 1:140 1:3,000 1:12,000 1:25,000 ≥

38. “Is lead poisoning a serious enough illness to warrant screening?”

39. Early Clinical Symptoms • Anorexia • Abdominal pain • Constipation • Anemia

40. Case Report: MMWR 3/23/2006 • Feb 2006: 4 year old dies in Minnesota of undiagnosed lead poisoning (BLL 180) • Reebok recall • Pediatrics, Dec 2006, 2548-51

41. Rare Clinical Symptoms Blood lead >70 µg/dL • Changes in mentation (encephalopathy) • Ataxia • Seizures • Coma • Death

42. Most Common Clinical Finding • Neuro-developmental compromise • Clear reduction in IQ inversely correlated with rising lead levels •  approximately 1/4 to 1/2 point decrease for every 1µg/dL rise in BLL

43. “What am I required to do?”

44. 1. Provide anticipatory guidance • At each periodic health assessment from 6 months - 72 months • Inform parents of risk of lead exposure to young children • especially deteriorating/disturbed lead-based paint & paint dust • particularly after begins crawling • particularly because of hand-mouth behavior

45. 2. Statewide Targeted Screening Policy • Test all children who receive services from publicly funded programs • Medi-Cal • Healthy Families • CHDP • WIC • @ ~12 months & ~24 months of age

46. 2. Statewide Targeted Screening Policy • Test children not in publicly funded programs who answer “yes” or “don’t know” to the following question: • Does your child live or spend a lot of time in a place built before 1978 that has chipped or peeling paint or has been recently renovated? • Any child not appropriately tested • Parent requests • Obvious risk factors present

47. “Doesn’t screening increase my paperwork?”

48. Guidance & Counseling • At each well baby and pre-school check • Provide simple written information • Follow BLL >/= 5 mcg/dL • ? Risks present • Interventions: • Hand-washing • Good nutrition • Infant stimulation

49. Other environmental interventions: • Check cans & cookware • Wash toys/ Wipe windowsills/ Wet mop • Remove shoes at door • Adult exposed from job: shower & change clothes • Close off area if remodeling

50. “Even if I find a child who is lead poisoned, can we do anything to improve the clinical outcome for this child or is the damage already done?”