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

AX6-31
Table AX6-3.1 (cont’d). Neurobehavioral Effects Associated with Environmental Lead Exposure in Adults
Reference, Study
Location, and Period Study Description Pb Measurement Findings, Interpretation
United States (cont’d)
Payton et al. (1998)
U.S.
Rhodes et al. (2003)
U.S.
Wright et al. (2003)
U.S.
141 healthy men in VA normal aging study
evaluated every 3 to 5 yrs with cognitive
battery and blood Pb and once a
measurement of patella and tibia bone Pb.
Statistics are confusing as it is not clear
when ANCOVA is used and how the
groups are created.
526 participants with mean age 67 yrs,
47% had education level of high school or
less. Mood symptoms evaluated with Brief
Symptom Inventory (BSI). Use of logistic
regression adjusting for covariates
examined association of BSI scales and
blood Pb and bone Pb levels.
736 healthy men (mean age 68) in
Normative Aging Study examined every 3
to 5 yrs were administered the Mini-
Mental State Exam (MMSE). Linear
regression examined relationship of
MMSE and blood Pb, patella and tibia
bone Pb measurements after adjusting for
covariates.
Mean blood Pb 6 µg/dL
Mean patella bone Pb 32
µg/g
Mean tibia bone Pb 23 µg/g
bone mineral
Mean blood Pb 6 µg/dL
Mean tibia Pb 22 µg/g
Mean patella Pb 32 µg/g
Mean blood Pb 5 µg/dL,
Mean patella bone Pb 30
µg/g
Mean tibia bone Pb 22 µg/g
Regressions adjusted for age and education found significant
relationship of blood Pb with Pattern Comparison (perceptual speed),
Vocabulary, Word List Memory, Constructional Praxis, Boston
Naming Test, and Verbal Fluency Test. Only for Constructional Praxis
were bone Pb and blood Pb significantly associated. Mechanism most
sensitive to low levels Pb exposure believed to be response speed.
Vocabulary is significantly associated with blood Pb. Education is
negatively correlated to bone and blood Pb. It is not clear how multiple
comparisons were handled
BSI found mood symptoms for anxiety and depression were potentially
associated with bone Pb levels. Education was inversely related to
bone Pb and high school graduates had significantly higher odds of
Global Severity Index and Positive Symptom Total.
Mean MMSE score 27. Relation of MMSE scores