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

AX4-12
Reference, Study
Location, and Period Study Description
United States
Hu et al. (1994)
U.S.
1991
Schwartz et al. (2000b)
U.S.
1995
Popovich et al. (2005)
Idaho
Canada
Fleming et al. (1997)
Canada
1994
Table AX4-5. Bone Lead Measurements in Occupationally-Exposed Subjects
Construction workers aged 23 to 67 yr
(n = 19). Examination of Bone Pb
and PbB as predictors of blood
pressure in construction workers.
Multivariate linear regression,
LOWESS smoothing.
Retired organolead employees (n =
543). Aim to determine influence of
PbB, chelatable Pb, and tibial Pb on
systolic and diastolic blood pressure.
108 former female smelter employees
and 99 referents to assess the PbB
versus bone Pb relationship.
Primary smelter workers, 367 active
and 14 retired.
PbB in 204 workers returning after a
10-mo strike ended in 1991.
Cumulative PbB index, K-shell
measures with 109 Cd source.
Lead Measurement (SD or range)
PbB in µg/dL, Bone Pb in µg/g Bone Mineral Findings, Interpretation
PbB 8.3 (±4.0), tibia Pb 9.8 (±9.5), patella Pb
13.9 (±13.6).
PbB 4.6 (±2.6), tibia Pb14.4 (±9.3). Tibia Pb was not associated with any blood
pressure measures.
Exposed: PbB 2.73 (±2.39), tibia 14.4 (±0.5)
Referents: PbB 1.25 (±2.10), tibia 3.22 (±0.50)
Pb concentrations in tibia and blood significantly
higher in the exposed group. Endogenous release
rate (µg Pb per dL blood/µg Pb/g bone) in
postmenopausal women was double the rate found in
premenopausal women (0.132 ± 0.019 vs. 0.067 ±
0.014).
Active (1975-81) median PbB 16.0, (1987-92)
median PbB 8.0, tibia range 0-150, calcaneus 0-250.
Retired tibia range 20-120, calcaneus 40-220.
Bone Pb-cumulative PbB index slopes larger for
retired compared with active workers, but not
significant.
Higher tibia bone Pb (and PbB) was
associated with use of estrogen (present or
former) in both the whole referent group and
postmenopausal women in the referent group.
Nonlinearities in cumulative PbB index and
tibia and calcaneus Pb suggest differences in
Pb transfer from whole blood to bone among
smelter employees. Contribution to PbB from
bone stores at any instant in time is similar for
all occupationally exposed populations, active
or retired.
Age-related variations in bone turnover are
not a dominant factor in endogenous exposure
of male lead workers. More rapid absorption
of Pb in calcaneus than tibia.