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

AX6-14
Table AX6-2.4. Effects of Lead on Academic Achievement in Children
Reference, Study
Location, and Period Study Description Pb Measurement Findings, Interpretation
United States
Lanphear et al. (2000)
U.S.
Needleman et al. (1990)
U.S.
Design: Cross-sectional. 4,853 U.S. children ages
six to 16 yrs enrolled in NHANES-III. Subjects
were administered the Arithmetic and Reading
subtests of the Wide Range Achievement Test-
Revised (WRATR). A number of medical and
sociodemographic covariates were assessed and
entered into multivariable models.
Design: Prospective cohort. Re-examination of the
Chelsea and Somerville cohort recruited in the
1970’s (Needleman et al., 1979). 132 adolescents
were recalled. Large battery of tests was
administered to examine neurobehavioral deficits
and academic achievement in high school and shortly
following graduation. Extensive assessment of
medical and sociodemographic covariates.
Blood Pb at time of testing
Geometric blood Pb 1.9
(SE 0.1) µg/dL
2.1% with blood Pb
∃10 µg/dL
Tooth (dentin) Pb
Tooth Pb median 8.2 µg/g
Following covariate adjustment, a statistically significant
relationship between blood Pb and WRATR performance
was found. A 0.70 point decrement in Arithmetic scores
and a 1 point decrement in Reading scores for each
1 µg/dL increase in blood Pb concentration was observed.
Statistically significant inverse relationships between blood
Pb levels and performance for both Reading and
Arithmetic subtests were found for children with blood Pb
concentrations 20 ppm were at higher risk
of dropping out of high school (adjusted OR = 5.8 [95%
CI: 1.4, 40.7]) and of having a reading disability (adjusted
OR = 5.8 [95% CI: 1.7, 19.7]). Higher dentin Pb levels
were also significantly associated with lower class
standing, increased absenteeism, and lower vocabulary and
grammatical reasoning scores on the Neurobehavioral
Evaluation System (NES). Authors conclude that undue
exposure to Pb has enduring and important effects on
objective parameters of success in life.