Lead Poisoning and Child IQ

1. EHOH 6614
Dana Baillet, Marisol Cruz, Ethan
Jamison, Breanna Kawasaki, and Meredith
Warman
April 2, 2014

2. • What is Lead?
• History of Lead Use
• Exposure
• Consequences of Exposure
• Case Studies
• Reforms
• How to Protect Yourself
• Resources
Photo retrieved from: http://periodictable.com/Elements/082/pictures.html

3. • Divalent cation (2 ions)
• Toxic substance
• Enzymes and proteins are distorted
• Various toxic properties
• Competes with calcium for binding sites, can
damage the central nervous system
• Prevents calcium from entering cells
• Hinder cellular respiration
• Impact the integrity of the blood-brain barrier
Needleman, H. (2004)
Photo retrieved from: http://images-of-elements.com/lead.php

4. • Second Century B.C.: Lead
used to sweeten wine
• The sweetness of lead used to
balance the natural tannic
flavor of wine
• Wine was an integral part of
life for upper-class Romans
• Early 19th Century: Used as
an insecticide in orchards
Needleman, H. (2004)
Wolz, S., Fenske, R. A., Simcox, N. J., Palcisko, G., & Kissel, J. C. (2003).

5. • Late 19th Century: Lead based paint found to have
toxic effects on children
• Brisbane, Australia 1904: Lead paint used in playground
equipment linked to poor health outcomes for children
• Australia: Lead banned from household use
• 1914: Lead poisoning in children first uncovered in
the United States
• Initial theory that lead exposure resulted in death or full
recovery
• 1970s: Further research links lead poisoning to
impaired cognitive function in children
Needleman, H. (2004)

6. • Most lead poisoning in children now is due to dust
and chips from deteriorating paint
• Dust and soil from airborne lead in gasoline and
dust from paint (playing in contaminated soil)
• Lead can cross the placenta and be in breast milk
• Other possible sources
Jacobs DE, Clickner RP, Zhou JY, et al. (2002); Lanphear, Matte, Rogers, et al. (1998); CDC (2002)

7. • Early symptoms
• Chronic fatigue
• Irritability
• Loss of appetite
• Stomach discomfort/constipation
• Low attention span
• Insomnia
US EPA ( 2013)

8. • Brain and nervous
system damage
• Reduced IQ
• Learning disabilities
• Mental retardation
• Behavioral problems
• Hyperactivity
• Developmental delays
• Anemia
• Liver and kidney damage
• Hearing loss
• Coma or Death
(in extreme cases)
US EPA ( 2014); NSC (2009)

9. • Deficits found at blood lead
levels (BLL) of <7.5 μg/dL
• More severe deficits occur at
lower BLL
• No apparent threshold for
cognitive impairment
• Prenatal exposure to lead
impacts cognitive
development
Lanphear (2005); Meyer (2008)

10. Impact of Low Blood Lead Concentrations on IQ
and School Performance in Chinese Children

11. • Objective: Relationship between blood lead
concentrations, children’s IQ, and school performance
• Overview:
• 1341 children (738 boys and 603 girls) from
Jintan, China
• Blood lead concentrations were measured when
children were 3–5 years old
• IQ was assessed using the Primary Scale of
Intelligence
• School performance was assessed by standardized
tests on 3 major subjects (Chinese, math, and
English) when children were 8–10 years old
Liu et al. (2013)

12. • Conclusion:
• Blood lead concentrations in early childhood, even
<10 μg/dL, have a long-term negative impact on
cognitive development
• Compared to children with blood lead
concentrations <8 μg/dL, those with blood lead
concentrations ≥ 8 μg/dL scored 2–3 points lower in
IQ and 5–6 points lower in school tests
• No significant differences in IQ or school tests
between children with blood lead concentrations
groups 8–10 and ≥ 10 μg/dL

13. Case Study 2
Early Childhood Lead Exposure & Academic Achievement:
Evidence From Detroit Public Schools, 2008–2010

14. • Objective: Long-term effects of early childhood lead
exposure on academic achievement among children in
Detroit Public Schools
• Overview:
• Linked early childhood blood lead testing surveillance
data from the Detroit Department of Health and
Wellness Promotion to educational testing data from
elementary and junior high school students
• Used data to investigate the effect of early childhood
lead exposure on academic achievement among these
children
• Data adjusted for grade
level, gender, race, language, maternal education, and
socioeconomic status Zhang et al. (2013)

15. • Conclusion:
• High blood lead levels before age 6 were strongly
associated with poor academic achievement in
grades 3, 5, and 8
• Negatively associated with academic
achievement in elementary and junior high
school, after adjusting for key potential
confounders
• The control of lead poisoning should focus on
primary prevention of lead exposure in children
• Need for development of special education
programs for students with lead poisoning

17. • Key of protection: preventing or eliminating exposure
• Know the history of your home (constructed before
1978?)
• First step: Getting your child’s blood lead levels tested
• Next: Identify possible points of exposure
• Paint, water, dust, soil, etc.
CDC (2005); CDPHE (2013); Lanphear (1998)

18. • Lead abatement can be done by contractors to
reduce lead sources in your home
• Parents should work at reducing childhood exposure
to paint chips or dust
• Not allowing your child to eat dirt or mouth metal
objects
• Give children foods rich in iron, vitamin C, and
calcium
• Use only cold water from the tap for drinking and
cooking
• Home test kits: see paint section in hardware stores
CDC (2005); Lanphear (1998

19. • The Colorado Department of Public Health and
Environment has in-state authority to regulate lead
under the Clean Air Act
• The Air Pollution Control Division certifies lead
contractors for abatement and home inspection
• Federal regulations require all realtors to
warn/notify new residents of lead hazards
• Colorado state regulations require renovators to
distribute an EPA-approved lead hazard information
pamphlet prior to any work in homes built before
1978
CDPHE (2013)

20. • Lead poisoning in children continues to be an
important global public health issue
• CDC considers lead poisoning the most preventable
environmental disease among young children
• There are many way to test for lead and to protect
your children from exposure

21. • Centers for Disease Control and Prevention. Managing Elevated Blood Lead Levels Among Young Children: Recommendations From the
Advisory Committee on Childhood Lead Poisoning Prevention. Atlanta, GA: Centers for Disease Control and Prevention; 2002. Available
at:www.cdc.gov/nceh/lead/CaseManagement/caseManage_main.htm. Accessed February 20th, 2014
• Centers for Disease Control and Prevention. Preventing Lead Poisoning in Young Children A Statement by the Centers for Disease Control
and Prevention. Atlanta, GA: Centers for Disease Control and Prevention; 2005. Available at:
http://www.cdc.gov/nceh/lead/publications/prevleadpoisoning.pdf Accessed February 26th, 2014
• Colorado Department of Health and Environment. Lead Safety Time. Colorado Department of Health and Environment Informational
Pamphlet. Colorado 2013. Available at: http://www.colorado.gov/cs/Satellite/CDPHE-AP/CBON/1251594599618 Accessed February 26th
2014
• Jacobs DE, Clickner RP, Zhou JY, et al. The prevalence of lead-based paint hazards in U.S. housing. Environ Health Perspect.2002;110 :A599–
A606
• Lanpher, Bruce P. Burgoon, David A. Rust, Steven w. Eberly, Shirley. Galke, Warren. Environmental Exposures to Lead and Urban Children’s
Blood Lead Level. Environmental Research, Section A 78,120-130 1998. Available at: http://www.ncbi.nlm.nih.gov/pubmed/9515067
Accessed February 26th, 2014
• Lanphear, Bruce P., Hornung, Richard, Khoury, Jane, Yolton, Kimberly, Baghurst, Peter, Bellinger, David C., . . . Roberts, Russell. (2005).
Low-Level Environmental Lead Exposure and Children’s Intellectual Function: An International Pooled Analysis. Environmental Health
Perspectives, 113(7), 894-899. doi: 10.1289/ehp.7688
• Lanphear BP, Matte TD, Rogers J, et al. The contribution of lead-contaminated house dust and residential soil to children's blood lead
levels. A pooled analysis of 12 epidemiologic studies. Environ Res.1998;79 :51– 68
• Liu, J., Li, L., Wang, Y., Yan, C., & Liu, X. (2013). Impact of low blood lead concentrations on IQ and school performance in Chinese children.
PLoS One, 8(5), e65230.
• Meyer, P. A., Brown, M. J., & Falk, H. (2008). Global approach to reducing lead exposure and poisoning. Mutat Res, 659(1-2), 166-175. doi:
10.1016/j.mrrev.2008.03.003
• Zhang, N., Baker, HW.., Tufts, M., Raymond, R.E., Salihu, H. and Michael R. Elliott. Early Childhood Lead Exposure and Academic
Achievement: Evidence From Detroit Public Schools, 2008–2010. AJPH: March 2013, Vol. 103, No. 3, pp. e72-e77.
• National Safety Council. (2009). LeadPoisoning Fact Sheet.
http://www.nsc.org/news_resources/Resources/Documents/Lead_Poisoning.pdf
• Needleman, H. (2004). Lead Poisoning. Annual Review of Medicine, 55, 209-222.
• United States Environmental Protection Agency. (2014, Feb. 20, 2014). Lead. Retrieved Feb. 2014, from http://www2.epa.gov/lead
• Wolz, S., Fenske, R. A., Simcox, N. J., Palcisko, G., & Kissel, J. C. (2003). Reidential Arsenic and Lead Levels in an Agricultural Community
with a History of Lead Arsenate Use. Environmental Research, 93, 293-300.