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

AX6-165
Table AX6-5.3 (cont’d). Effects of Lead on Cardiovascular Mortality
Reference, Study
Location, and
Period Study Description Pb Measurement Findings, Interpretation
Europe
Gerhardsson et al.
(1995)
Europe-southern
Sweden
1969-1989
Møller and
Kristensen (1992)
Europe-Denmark-
Copenhagen
County-Glostrup
Population Studies
1976-1990
664 male workers at a secondary Pb
smelter had blood Pb tested every 2-3
mos since 1969. The past blood Pb level
of 201 workers who had been working at
the plant from before 1969 was estimated
from their 1969 results. Median (10th
percentile, 90th percentile) yr of birth
was 1943 (1918, 1960). Median (10th
percentile, 90th percentile) duration of
employment was 2.8 yrs (0.3, 25.7) and
median (10th percentile, 90th percentile)
duration of follow up was 13.8 yrs (2.8,
20.9). A total of 8706 person-yrs were
represented in the study. Standardized
mortality ratios based on county
mortality tables by calendar yr, cause,
sex and five-yr age group were
calculated. Cardiovascular diseases were
coded by ICD-8 from death certificates.
See Møller et al. (1992) entry in Blood
Pressure and Hypertension for results of
cardiovascular disease and coronary heart
disease mortality.
Arithmetic mean blood
Pb levels dropped from
~62 µg/dL in 1969 to
~33 µg/dL in 1985.
95% CI were difficult
to extract from the
presented graph, but
appeared to be no more
than 5-6 µg/dL about
the mean.
All cardiovascular disease mortality (ICD-8 390-458) was significantly elevated
above that expected from the county mortality tables (SMR = 1.46 [95% CI:
1.05, 2.02]), with 39 of the 85 deaths observed in the cohort. For just ischemic
heart disease (ICD-8 410-414), SMR = 1.72 (95% CI: 1.20, 2.42) in the plant
workers with 34 of the 85 deaths observed in the cohort. There were no deaths
recorded for cerebrovascular diseases (ICD-9 430-438). There was no apparent
concentration-response relationship, using peak blood Pb and time-integrated
blood Pb.
Problems inherent in using standardized mortality ratios in such mortality studies
have been discussed above. The sample size was too small (85 all cause deaths
among 664 workers) to interpret non-significant results.