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

AX4-20
Reference, Study
Location, and
Period Study Description
Canada
Brito et al. (2000)
Canada
1993-98
Brito et al. (2002)
Canada
1994, 1999
Aims were to: (i) investigate the
long term human Pb metabolism by
measuring the change of Pb
concentration in the tibia and
calcaneus between 1993 and 1998;
and (ii) assess whether improved
industrial hygiene was resulting in a
slow accumulation of Pb in an
exposed workforce. 101 workers in a
secondary lead smelter, 51 subjects
had similar bone Pb measurements in
1993. Most other subjects had been
hired since 1993. Cumulative PbB
index. Linear regressions.
Evaluated endogenous release of Pb
from bone to blood in 204 exposed
subjects resuming their duties after a
10-mo strike in a primary lead
smelter in 1991. Bone Pb ( 109 Cd
source) measured in the tibia and
calcaneus in 1994 (Fleming et al.,
1997) and 1999. A linear model
used to predict the current PbB upon
the level of lead in bone.
327 subjects available on both
occasions. Group H higher PbB and
Group L lower PbB.
Table AX4-6 (cont’d). Bone Lead Contribution to PbB
Lead Measurement (SD or range)
PbB in µg/dL, Bone Pb in µg/g Bone Mineral Findings, Interpretation
Repeats (n = 51)
1993: Tibia 39 (±19), calcaneus 64 (±36).
1998: Tibia 33 (±18), calcaneus 65 (±38).
Non-repeats (n = 50)
1998: Tibia 15 (±16), calcaneus 13 (±18).
Tibia Pb decreased significantly (p