Deficits in psychologic and classroom performance of children with elevated dentine lead levels.
Level 4 - case-series / case-control
Cross-sectional comparative observational study evaluating neuropsychological and behavioral outcomes across dentine lead levels
PubMed 763299 · doi:10.1056/NEJM197903293001301
What was done
Researchers evaluated the neuropsychologic and behavioral effects of asymptomatic childhood lead exposure. Performance on the Wechsler Intelligence Scale for Children (Revised), verbal subtests, three auditory/speech processing measures, and an attention measure was compared between 58 children with high dentine lead levels and 100 children with low dentine lead levels, adjusting for 39 potential confounding variables via analysis of variance. Additionally, classroom behavior was assessed via teacher questionnaires across the broader cohort of 2,146 children whose teeth were analyzed for lead.
What was found
Children with high dentine lead levels scored significantly lower on the full WISC-R, verbal subtests, three measures of auditory or speech processing, and an attention measure compared to children with low lead levels. ANOVA indicated that these differences persisted after accounting for 39 covariates. Across the full sample of 2,146 children, the frequency of non-adaptive classroom behavior increased in a dose-related fashion with increasing dentine lead levels. The abstract reports no exact test scores, effect sizes, confidence intervals, or p-values.
Why it matters
This study demonstrated that low-level, subclinical lead exposure is associated with measurable intellectual, attentional, and behavioral deficits in school-aged children.
Limits
The study is observational and cross-sectional, precluding definitive causal inference. The abstract omits exact numerical scores, effect sizes, variance, and p-values for both the cognitive tests and the behavioral assessments.
Cited by
- supports Studies measuring lead levels in children's teeth found associations between lead exposure and severe behavioral issues, aggression, and ADHD.