Attentional correlates of dentin and bone lead levels in adolescents.
Level 3 - non-randomized controlled study
Non-randomized follow-up cohort study assessing past and present lead biomarkers against neuropsychological attention outcomes
PubMed 8161248 · doi:10.1080/00039896.1994.9937461
What was done
Researchers evaluated 79 participants aged 19 and 20 years on a neuropsychological battery assessing attention factors. Performance was compared against early-life lead exposure (measured in deciduous teeth dentin) and cumulative or current exposure (tibia and patella bone lead by K-X-ray fluorescence, and current blood lead), along with the ALA-D isozyme phenotype.
What was found
Dentin lead levels averaged 14 micrograms/g, and most bone lead levels were below 10 micrograms/g. Dentin lead was inversely related to performance on two of four attention factors: focus-execute and shift. Few significant associations were detected between bone lead levels and performance. Five participants with the ALA-D 1-2 isozyme phenotype tended to show more optimal scores. Exact effect estimates, test statistics, and p-values were not reported in the abstract.
Why it matters
This study provides evidence that early childhood lead exposure may exert long-lasting, selective impairments on executive and self-regulatory attention functions into early adulthood.
Limits
The sample size is modest (79 participants), with very few individuals (5) carrying the ALA-D 1-2 phenotype. The abstract reports no numerical effect sizes, p-values, or confidence intervals, and does not describe adjustments for potential confounding variables such as socioeconomic status or IQ.
Cited by
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