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 Health Medical Officer Childhood Lead Poisoning Prevention Branch California Department of Health Services

2. “Why should I screen. ” “What difference does it make anyway
“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
Gastrointestinal route most common for children.
Other Factors: exposure to lead, behavior (eg: hand to mouth common in all young children, pica occurs in children and adults, important in pregnant women)
*Environmental Health Perspectives 1993, 101:

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
Insidious
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
Inverse relationship between IQ and Lead Level
110
105
0-4.9
≥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. Effects of a Small Shift in IQ Distribution in a Population of 260 Million
Normal: mean = 100
The effect of low lead exposures on IQ is relatively small for the average individual, reducing IQ by only a few points. It’s important to remember, however, that impacts that are marginal for the average individual can have profound effects when applied over large populations, in effect, shifting the population distribution curve for the parameter of concern. That parameter might be IQ, as in this case, or any other cognitive or behavioral function such as memory or attention. Such shifts have dramatic effects at the high and low ends of the distribution curve, often referred to as the “tails.” This is illustrated in a hypothetical population of 260 million with an average IQ of 100. The area under the left “tail” of the curve represents the 2.3% of the population with an IQ <70, the score used to define mental retardation. In a population of 260 million, about 6 million people would fall below this line.
Source: Weiss, B. Endocrine disruptors and sexually dimorphic behaviors; a question of heads and tails. Neurotox 18: , 1997.
Graphics: adapted from above reference
6.0 million
6.0 million
“special health &
educational needs"
"gifted"
160
140
120
100 80 60 40 70
130
I.Q.
Adapted from Pediatric Environmental Toolkit

11. 5 Point Decrease in Mean IQ
This chart shows what happens when the average IQ is shifted by 5 points from 100 to 95. Now, 3.2% of the population, or 9.4 million people have an IQ below 70. This represents more than a 50% increase in the numbers of mentally retarded. The numbers of gifted, defined as those with IQ’s greater than 130, have declined by more than 50% from 6 million to 2.4 million. Thus a small shift in average IQ results in greatly increased need for special education and services, as well as diminished intellectual capacity within the population as a whole.
Source: Weiss, B. Endocrine disruptors and sexually dimorphic behaviors; a question of heads and tails. Neurotox 18: , 1997.
Graphics: adapted from above reference
57% DECREASE
9.4 million
2.4 million
“special health &
educational needs"
"gifted"
57% INCREASE
160
140
120
100 80 60 40 70
130
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:
Rothenberg & Rothenberg, Environmental Health Perspectives, Sept 2005, 113:

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):

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. Top Ten States with pre-1950 Housing
0.5 1
1.5 2
2.5 3
3.5 4 NY PA CA IL OH MI MA NJ TX WI
Top Ten States
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 Lead-Glazed Stoneware CAZUELA Consuela Soil Glaze
Low-heat
Lead-Glazed
Stoneware

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

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

29. Lead in Imported Jewelry
potentially

30. Lead in Folk Remedies
Ayruvedic medications 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
More likely to have lower income
More likely to live in poor substandard
*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
1:12,000
1:3,000
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
1:12,000
1:3,000
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,

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
Kaiser handout

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?”

51. Case study from Kaiser Vallejo
BLL = 17.4
Lab auto reports to state contacts cty clpp
Call froml PHN
Home visit & counseling & initial investigation
Rept level 3months
BLL = 8
Further info that child had visited A&U & cousins who recently emigrated from Mexico
Home candy
Tested cousins & counseled family via Span-speaking interpreter
Enrolled in Healthy families (Kaiser)
Found: New 18 mo. old male (Medi-Cal) BLL=17.4

52. Initiate environmental intervention:
Case management:
Automatic referral to county CLPPP
BLL > 10 mcg/dl
Child Lead Poisoning Prevention Program does the work:
Risk/exposure queries
Environmental investigation
Identify other affected children/family members
Tailored education
Referral to WIC
Feedback from CLPPP
BLL = 17.4
Lab auto reports to state contacts cty clpp
Call froml PHN
Home visit & counseling & initial investigation
Rept level 3months
BLL = 8
Further info that child had visited A&U & cousins who recently emigrated from Mexico
Home candy
Tested cousins & counseled family via Span-speaking interpreter
Enrolled in Healthy families (Kaiser)

53. _ Prevent further neuro-developmental compromise:
Arrange for developmental evaluation
Referral DDS/Early Start if needed
Follow-up by CLPPP (including family)
BLL = 17.4
Lab auto reports to state contacts cty clpp
Call froml PHN
Home visit & counseling & initial investigation
Rept level 3months
BLL = 8
Further info that child had visited A&U & cousins who recently emigrated from Mexico
Home candy
Tested cousins & counseled family via Span-speaking interpreter
Enrolled in Healthy families (Kaiser)

54. Am I complying with the standard of care?
Provide anticipatory guidance about lead hazards to all parents
Lead test all publicly assisted children
Ask screening question of other children
Remove source(s) of lead when possible
Request assistance of local county CLPP when BLL≥ 10mcg/dL
Results: compliance with current standard of care regulations in California

55. What should I do if I need to chelate?
Very rare
Discuss with experienced consultant
See DHS internet site
Current list of consultants
Treatment matrix

56. Special Recommendations:
Screen new immigrants and refugees
esp. adopted toddlers from developing countries
exposed to unknown risks
Consider screening pregnant women
household member works in occupation with significant risk of lead exposure
lead poisoned child living in household
pica/other risks
refugee or new immigrant

57. Why be concerned about lead in the perinatal period?
Lead readily transferred to the fetus during pregnancy
Developing fetus especially vulnerable to effects of lead
Fetal blood lead levels estimated to be 80%-90% of maternal levels based on umbilical cord lead level
Studies have found a correlation with prenatal lead exposure and:
- Reduced intelligence
- Behavior problems
- Developmental delays

58. So what else can I do?
Identify & eliminate lead sources to prevent further exposure to the mother and baby
If occupational source: refer to Occupational Lead Poisoning Prevention Program
If mother < 21 & meets case definition: eligible for case management services thru DHS CLPPP
Refer family members for blood lead test
Encourage good nutritional practices
Recommend avoiding tobacco/alcohol during pregnancy

59. California DHS Website Information:
(provider references)
(fact sheet)
(treatment matrix)
(home page)

60. E-mail address: srosenbe@dhs.ca.gov
The End
address:

62. Estimated Losses in IQ if Lead Had Remained in Gasoline 1970–1990
(Gilbert & Weiss, NeuroToxicology 2006, 27:693–701)