Soil and lead poisoning

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Soil and lead poisoning

• Mary Jo Trepka, MD, MSPH

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Outline

• Importance of childhood lead poisoning
• Childhood lead poisoning in Miami-Dade County
• Risk factors in Miami-Dade County
• Health department services
• Relevance to students
• What we still dont know

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What is so important about childhood lead
poisoning?

• Can lead to permanently lowered IQs
• Children more susceptible
• Ubiquitous in environment
• Urban poor and minorities disproportionately
  affected

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What is a safe lead level?

• Current action level 10 µg/dL
• Estimated 2.6-5.8 point IQ decline for increase
  from 10 to 20 µg/dL
• Under 10 µg/dL safe?
• 7.4 point IQ decline for 1-10 µg/dL
• Cognitive and academic deficits for BLL lt 5 µg/dL

(Schwartz, et al, Env Res 1994, Bellinger, et al
Pediatrics 1992, Canfield, et al NEJM 2003,
Lanphear, et al Pub Health Rep 2000)
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What is so important about childhood lead
poisoning?

• Can lead to permanently lowered IQs
• Children more susceptible
• Ubiquitous in environment
• Urban poor and minorities disproportionately
  affected

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What is so important about childhood lead
poisoning?

• Can lead to permanently lowered IQs
• Children more susceptible
• Ubiquitous in environment
• Urban poor and minorities disproportionately
  affected

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Sources of lead

• Soil
• Dust
• Paint
• Pottery
• Occupation/hobbies
• Folk remedies
• Tiles
• Water

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Sources of lead

• Soil
• Dust
• Paint
• Pottery
• Occupation/hobbies
• Folk remedies
• Tiles
• Water

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Occupations with possible lead exposure

• Auto repair/radiator repair
• Painting
• Construction work
• Steel welding and cutting
• Plumbing
• Police work
• Maritime industry

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Hobbies with possible lead exposure

• Fishing sinkers
• Working with cars, car parts, or car batteries
• Painting
• Stained-leaded glass work
• Shooting guns at firing ranges
• Working with model cars or boats
• Pottery work

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What is so important about childhood lead
poisoning?

• Can lead to permanently lowered IQs
• Children more susceptible
• Ubiquitous in environment
• Urban poor and minorities disproportionately
  affected

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NHANES blood lead levels among children aged 1-5
years, United States, 1976-2000
Source CDC MMWR 200352SS10
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Prevalence of lead poisoning by housing age

• Nationwide 2.2 of 1-5 year-olds
• Housing
• 8.6 Pre-1946
• 4.6 1946-73
• 1.6 Post-1973

Source CDC, 1999-2000 NHANES
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Prevalence of lead poisoning by race/ethnicity
and income among those in pre-1946 housing

• Differs by race/ethnicity
• 22 black
• 13 Mexican American
• 6 white
• Differs by income
• 16 low
• 4 middle
• 1 high

Source CDC, 1999-2000 NHANES
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Childhood lead poisoning in Miami-Dade County

• Prevalence
• Florida 3.2 (Hopkins, et al, J Fla Med Assoc.
  1995)
• Miami-Dade
• Countywide unknown
• Central urban area estimated 8
• Surveillance average 431 cases a year among
  children (1998-2002)
• Underscreening
• Florida 17 (GAO Report)
• Miami-Dade 23 (analysis of Medicaid data)

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Lead poisoning cases by gender, Miami-Dade County
2002
Source Miami-Dade County Health Department,
Vital and Morbidity Statistics 2002
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Population lt 6 years, 2000, and reported lead
poisoning cases by race and ethnicity,
1999-2001, Miami-Dade County
Population
Cases
Source 2000 US Census and Miami-Dade County
Health Department
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Sources of lead hazards based on environmental
home inspections

• 188 inspections
• 89 (47) inspections found no hazards (55 of
  these inspections in imported cases)
• Other sources fishing weights, parental
  occupations, hobbies, water, objects/statues

Source Miami-Dade County Health Department
Childhood Lead Poisoning Prevention Program 2003
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Risk factors for lead poisoning in Miami-Dade
County

• Living in a home built prior to 1950
• Living in central urban area
• Low socio-economic status
• Living in a recently remodeled home
• Sibling or playmate with lead poisoning
• Refugee status

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Lead poisoning prevalence among children screened
at the Refugee Health Assessment Center,July
1, 2001 to June 30, 2002
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Childhood Lead Poisoning Prevention Program

• Screening
• Surveillance
• Follow-up
• Public and professional education
• Primary prevention
• Evaluation

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Relevance to students lives

• May live in neighborhoods with soil lead hazards
  and may have younger siblings at risk
• May become parents and will need to know about
  preventing lead poisoning in their own children
• May be exposed in workplace or during hobbies in
  future

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What we still dont know

• How to remove lead from soil
• How to cover soil to prevent exposure
• If there is a safe lead level
• Extent of behavioral effects
• How to bring about lead abatement
• Risk factors among immigrant children