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

AX6-5
Table AX6-2.1 (cont’d). Prospective Longitudinal Cohort Studies of Neurocognitive Ability in Children
Reference, Study
Location, and Period Study Description Pb Measurement Findings, Interpretation
Europe
Wasserman et al. (1992,
1994, 2003); Factor-
Litvak et al. (1999)
Yugoslavia
Birth cohort of ~300-400 infants followed since
birth residing in two towns in Kosovo, Yugoslavia,
one group near a longstanding Pb smelter and
battery manufacturing facility and another in a
relatively unexposed location 25 miles away.
Intellectual status was monitored from 2 to
10-12 yrs of age with the Bayley Scales of Infant
Development, McCarthy Scales of Children’s
Abilities, and WISCIII. Extensive assessment of
medical and sociodemographic covariates.
Maternal prenatal, umbilical
cord, and serial postnatal
blood Pb
Maternal blood Pb in exposed
area 19.9 (SD 7.7) µg/dL,
unexposed area 5.6 (SD 2.0)
µg/dL
Umbilical cord blood Pb in
exposed area 22.2 (SD 8.1)
µg/dL, unexposed area 5.5
(SD 3.3) µg/dL
Blood Pb at 2 yrs in
exposed area 35.4 µg/dL,
unexposed area 8.5 µg/dL
Postnatal blood Pb increment from 10 to 30 µg/dL at 2 yrs
of age associated with covariate-adjusted decline of 2.5
points in Bayley MDI. Maternal and cord blood Pb not
consistently associated with Bayley outcomes. Higher
prenatal and cord blood Pb concentrations associated with
lower McCarthy General Cognitive Index (GCI) scores at
4 yrs. Scores on the Perceptual-Performance subscale
particularly affected. After covariate-adjustment, children
of mothers with prenatal blood Pb levels >20 µg/dL scored
a full standard deviation below children in the lowest
exposure group (