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

AX6-186
Table AX6-7.2. Key Occupational Studies of Lead Exposure and Cancer
Reference, Study
Location, and Period
United States
Study Description Pb Measurement Findings and Interpretation
Steenland et al. (1992)
(follow-up of Selevan
et al. (1985)
U.S.
1940-1988
Wong and Harris
(2000)
(follow-up of Cooper
et al. (1985)
U.S.
1947-1995
Cohort design.
1,990 male workers employed for
at least 1 yr in a Pb-exposed
department at a U.S. Pb smelter
in Idaho during 1940-1965.
Mortality traced through 1988 to
determine cause of death.
SMR computed for workers vs.
national rates for age-comparable
counterparts.
Cohort design.
Pb battery plant (4,518) and smelter
(2,300) workers.
Worker mortality was followed up
through 1995.
Cause of death was identified from
death certificates.
Mortality was compared with U.S.
national age-, calendar-yr-, and genderspecific
rates to compute the SMR.
(See additional entry for nested study
of stomach cancer.)
Exposure categorizations based on
airborne Pb measurements from
1975 survey. High-Pb-exposure
subgroup consisted of 1,436 workers
from departments with an avg of least
0.2 mg/m 3 airborne Pb or ≥50% of
jobs showing 0.40 mg/m 3 or greater.
Mean blood Pb 56 µg/dL in 1976.
Workers were evaluated as a whole,
and also as separate battery plant and
smelter worker populations.
Job histories were also used to
stratify workers by cumulative yrs of
employment (1-9, 10-19, 20+), date
of hire (pre-1946 vs. 1946 on), and
lag between exposure and cancer
(34 yrs). Mean blood
Pb 80 µg/dL during 1947-72 among
smelter workers, 63 µg/dL among
battery workers.
SMR (95% CI); number of deaths
Total cohort:
Nonsignificantly elevated RRs: kidney, bladder, stomach, and lung
cancer.
High-Pb-exposure subgroup:
Kidney 2.39 (1.03, 4.71); 8
Bladder 1.33 (0.48, 2.90); 6
Stomach 1.28 (0.61, 2.34); 10
Lung 1.11 (0.82, 1.47); 49
No control for smoking or exposure to other metals.
SMR (95% CI)
Battery plant workers:
All cancer 1.05 (0.97, 1.13)
All respiratory 1.13 (0.98, 1.29)
Stomach 1.53 (1.12, 2.05)
Lung, trachea, bronchus 1.14 ( 0.99, 1.30)
Thyroid, Hodgkin’s: nonsignificant
Bladder 0.49 (0.23, 0.90)
Smelter workers:
Digestive, respiratory, thyroid: nonsignificant
Lung 1.22 (1.00, 1.47)
Battery plant and smelter workers combined:
All cancer 1.04 (0.97, 1.11)
All respiratory 1.15 (1.03, 1.28)
Stomach 1.47 (1.13, 1.90)
Lung, trachea, bronchus 1.16 ( 1.04, 1.30)
Thyroid/endocrine 3.08 (1.33, 6.07)
Lung and stomach risks lower pre-1946 hires; higher for workers
employed 10-19 yrs than 19 yrs; SMRs peaked
with 20- to 34-yr latency for lung, but