Air Quality Criteria for Lead Volume II of II - (NEPIS)(EPA) - US ...

AX6-18
Table AX6-2.5 (cont’d). Effects of Lead on Specific Cognitive Abilities in Children — Attention/Executive Functions,
Learning, and Visual-spatial Skills
Reference, Study
Location, and Period Study Description Pb Measurement Findings, Interpretation
United States (cont’d)
Ris et al. (2004)
U.S.
Design: Prospective longitudinal. 195 subjects from
the Cincinnati Pb Study were administered an
extensive and comprehensive neuropsychological
battery at 16-17 yrs of age. Domains assessed
included Executive Functions, Attention, Memory,
Achievement, Verbal Skills, Visuoconstructional,
and Fine Motor. Factor scores transformed to ranks
derived from a principal components factor analysis
of the neuropsychological test scores were the
primary outcome variables. Extensive measures on
medical and sociodemographic covariates.
Prenatal (maternal) and
serial postnatal blood Pb
assessments
Prenatal blood Pb 8.3
(SD 3.7) µg/dL
Blood Pb at 2 yrs 17.4
(SD 8.8) µg/dL
Following covariate adjustment, strongest associations
between Pb exposure and performance were observed for
factor scores derived from the Attention component, which
included high loadings on variables from the Conners
Continuous Performance Test. This relationship was
strongest in males. Authors speculate that since the
incidence of Attention Deficit/Hyperactivity Disorder is
greater in males in general, early exposure to Pb may
exacerbate a latent potential for such problems.