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

AX6-164
Table AX6-5.3 (cont’d). Effects of Lead on Cardiovascular Mortality
Reference, Study
Location, and
Period Study Description Pb Measurement Findings, Interpretation
United States (cont’d)
Steenland et al.
(1992)
U.S.-Idaho
>1941 to 1988
The death certificates of 1028 males of
the 1990 who worked at a smelter plant
at least one yr between 1940 and 1965
were examined to construct standardized
mortality ratios (SMR) for various ICD-9
disease classifications using the U.S.
population as a referent group.
In 1976 blood Pb of
173 workers avgd (SD)
56.3 µg/dL (12.9). Air
Pb was measured in
1975 at 3.1 mg/m 3 in
208 personal 8-h
samples. High Pb
departments in the plant
were defined as those
exceeding 0.2 mg/m 3 in
the 1975 survey.
Non-malignant respiratory disease and accidents accounted for most of the
significantly elevated SMR in the group. SMRs were not significantly elevated
for ischemic heart disease (410-414), SMR = 0.94 (95% CI: 0.84, 1.05);
hypertension with heart disease (402, 404), SMR = 0.97 (95% CI: 0.53, 1.63);
hypertension with no heart disease (401, 403, 405), SMR = 1.73 (95% CI: 0.63,
3.77); or cerebrovascular diseases (430-436), SMR = 1.05 (95% CI: 0.82, 1.32).
Similar results were found for the people working in the “high Pb departments.”
Though there is no doubt that this group was highly exposed to Pb, exposure
characterization over the working lifetime was not well defined, few blood Pb
data were available, and poor demographic data for the exposed group only
allowed a comparison with total U.S. population. As is usual with occupationally
exposed groups, selection bias may influence results. No smoking data were
available for the group. In industrial conditions smoking will be confounded
with other Pb exposure (constant hand to mouth behavior on the plant floor will
exposure smokers to more Pb via the oral route than in non-smokers).