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. 2007 Aug;115(8):1242-7.
doi: 10.1289/ehp.9994.

The relationship between early childhood blood lead levels and performance on end-of-grade tests

Marie Lynn Miranda  1 , Dohyeong Kim, M Alicia Overstreet Galeano, Christopher J Paul, Andrew P Hull, S Philip Morgan
Affiliations

The relationship between early childhood blood lead levels and performance on end-of-grade tests

Marie Lynn Miranda et al. Environ Health Perspect. 2007 Aug.

Abstract

Background: Childhood lead poisoning remains a critical environmental health concern. Low-level lead exposure has been linked to decreased performance on standardized IQ tests for school-aged children.

Objective: In this study we sought to determine whether blood lead levels in early childhood are related to educational achievement in early elementary school as measured by performance on end-of-grade (EOG) testing.

Methods: Educational testing data for 4th-grade students from the 2000-2004 North Carolina Education Research Data Center were linked to blood lead surveillance data for seven counties in North Carolina and then analyzed using exploratory and multivariate statistical methods.

Results: The discernible impact of blood lead levels on EOG testing is demonstrated for early childhood blood lead levels as low as 2 microg/dL. A blood lead level of 5 microg/dL is associated with a decline in EOG reading (and mathematics) scores that is roughly equal to 15% (14%) of the interquartile range, and this impact is very significant in comparison with the effects of covariates typically considered profoundly influential on educational outcomes. Early childhood lead exposures appear to have more impact on performance on the reading than on the mathematics portions of the tests.

Conclusions: Our emphasis on population-level analyses of children who are roughly the same age linked to previous (rather than contemporaneous) blood lead levels using achievement (rather than aptitude) outcome complements the important work in this area by previous researchers. Our results suggest that the relationship between blood lead levels and cognitive outcomes are robust across outcome measures and at low levels of lead exposure.

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Figures

Figure 1
Figure 1
Study counties in North Carolina.
Figure 2
Figure 2
Distribution of blood lead levels among white and black children.
Figure 3
Figure 3
4th-grade mean Reading EOG test results stratified by blood lead levels.
Figure 4
Figure 4
Percent of students failing 4th-grade Reading EOG.
Figure 5
Figure 5
Comparing model results for 4th-grade Reading score. Based on a referent individual who was screened at 2 years of age and is a white female, living in Wake County, parents with a high school education, not enrolled in the school lunch program, and who does not use a computer every day. Baseline score is 257.1.
Figure 6
Figure 6
Comparing model results for 4th-grade Mathematics scores. Based on a referent individual who was screened at 2 years of age and is a white female, living in Wake County, parents with a high school education, not enrolled in the school lunch program, and who does not use a computer every day. Baseline score is 262.6.
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References

    1. Bacharach VR, Baumeister AA. Effects of maternal intelligence, marital status, income, and home environment on cognitive development of low birthweight infants. J Pediatr Psychol. 1998;23(3):197–205. - PubMed
    1. Bellinger DC, Stiles KM, Needleman HL. Low-level lead exposure, intelligence and academic achievement: a long-term follow-up study. Pediatrics. 1992;90(6):855–861. - PubMed
    1. Canfield RL, Henderson CR, Cory-Slechta DA, Cox C, Jusko TA, Lanphear BP. Intellectual impairment in children with blood lead concentrations below 10 μg per deciliter. N Engl J Med. 2003;348(16):1517–1526. - PMC - PubMed
    1. CDC. Screening Young Children for Lead Poisoning: Guidance for State and Local Public Health Officials. Atlanta, GA: Centers for Disease Control and Prevention; 1997.
    1. CDC. Laboratory Standardization: Lead. Atlanta, GA:Centers for Disease Control and Prevention. 2006. [[accessed 21 September 2006]]. Available: http://www.cdc.gov/nceh/dls/lead.htm.

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