Early childhood lead exposure and the persistence of educational consequences into adolescence.
Blood lead level
Children
Cognitive development
Education
Lead
Journal
Environmental research
ISSN: 1096-0953
Titre abrégé: Environ Res
Pays: Netherlands
ID NLM: 0147621
Informations de publication
Date de publication:
11 2019
11 2019
Historique:
received:
18
04
2019
revised:
11
07
2019
accepted:
08
08
2019
pubmed:
2
9
2019
medline:
25
4
2020
entrez:
2
9
2019
Statut:
ppublish
Résumé
There is consensus that early childhood lead exposure causes adverse cognitive and behavioral effects, even at blood lead levels (BLL) below 5 μg/dL. What has not been established is to what extent the effects of childhood lead exposure persist across grades. To measure the effects of early childhood lead exposure (BLL 1-10 μg/dL) on educational performance from grades 3-8; to determine if effects in lower grades persist as a child progresses through school; and if so, to characterize the pattern of persistence. We examine data from 560,624 children living in North Carolina between 2000 and 2012 with a BLL ≤10 μg/dL measured between age 0-5 years. Children are matched to their standardized math and reading scores for grades 3-8, creating an unbalanced panel of 2,344,358 student-year observations. We use socio-economic, demographic, and school information along with matching techniques to control for confounding effects. We find that early childhood exposure to low lead levels caused persistent deficits in educational performance across grades. In each grade (3-8), children with higher blood lead levels had, on average, lower percentile scores in both math and reading than children with lower blood lead levels. In our primary model, we find that children with BLL = 5 μg/dL in early childhood ranked 0.90-1.20 (1.35-1.55) percentiles lower than children with BLL ≤ 1 μg/dL on math (reading) tests during grades 3-8. As children progressed through school, the average percentile deficit in their test scores remained stable. Our study shows that the adverse effects of early childhood exposure to low lead levels persist through early adolescence, and that the magnitude of the test-score percentile deficit remains steady between grades 3-8.
Sections du résumé
BACKGROUND
There is consensus that early childhood lead exposure causes adverse cognitive and behavioral effects, even at blood lead levels (BLL) below 5 μg/dL. What has not been established is to what extent the effects of childhood lead exposure persist across grades.
OBJECTIVE
To measure the effects of early childhood lead exposure (BLL 1-10 μg/dL) on educational performance from grades 3-8; to determine if effects in lower grades persist as a child progresses through school; and if so, to characterize the pattern of persistence.
METHODS
We examine data from 560,624 children living in North Carolina between 2000 and 2012 with a BLL ≤10 μg/dL measured between age 0-5 years. Children are matched to their standardized math and reading scores for grades 3-8, creating an unbalanced panel of 2,344,358 student-year observations. We use socio-economic, demographic, and school information along with matching techniques to control for confounding effects.
RESULTS
We find that early childhood exposure to low lead levels caused persistent deficits in educational performance across grades. In each grade (3-8), children with higher blood lead levels had, on average, lower percentile scores in both math and reading than children with lower blood lead levels. In our primary model, we find that children with BLL = 5 μg/dL in early childhood ranked 0.90-1.20 (1.35-1.55) percentiles lower than children with BLL ≤ 1 μg/dL on math (reading) tests during grades 3-8. As children progressed through school, the average percentile deficit in their test scores remained stable.
CONCLUSIONS
Our study shows that the adverse effects of early childhood exposure to low lead levels persist through early adolescence, and that the magnitude of the test-score percentile deficit remains steady between grades 3-8.
Identifiants
pubmed: 31473504
pii: S0013-9351(19)30440-2
doi: 10.1016/j.envres.2019.108643
pmc: PMC7038535
mid: NIHMS1553099
pii:
doi:
Substances chimiques
Lead
2P299V784P
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
108643Subventions
Organisme : Intramural EPA
ID : EPA999999
Pays : United States
Informations de copyright
Copyright © 2019 Elsevier Inc. All rights reserved.
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