BACKGROUND: High levels of cadmium exposure are known to cause emphysema in occupationally
exposed workers, but little has been reported to date on the association between chronic environmental
cadmium exposure and pulmonary function.
OBJECTIVE: In this study we examined the association between pulmonary function and cadmium
body burden in a subcohort of the Normative Aging Study, a community-based study of aging.
METHODS: We examined 96 men who had cadmium measured in single 24-hr urinary specimens
collected in 1994–1995 and who had one to three tests of pulmonary function between 1994 and
2002 (a total of 222 observations). We used mixed-effect models to predict pulmonary function
based on individual 24-hr urinary cadmium output, adjusted for age, height, time elapsed from the
baseline, and smoking status. We assessed effect modification by smoking status.
RESULTS: Among all subjects, a single log-unit increase in baseline urinary cadmium was inversely
associated with forced expiratory volume in 1 sec (FEV1) percent predicted [β = –7.56%; 95% confidence
interval (CI) –13.59% to –1.53%]; forced vital capacity (FVC) percent predicted (β =
–2.70%; 95% CI –7.39% to 1.99%), and FEV1/FVC ratio (β = –4.13%; 95% CI –7.61% to
–0.66%). In models including an interaction between urinary cadmium and smoking status, there
was a graded, statistically significant reduction in FEV1/FVC ratio across smoking status in association
with urinary cadmium.
CONCLUSIONS: This study suggests that chronic cadmium exposure is associated with reduced pulmonary
function, and cigarette smoking modifies this association. These results should be interpreted
with caution because the sample size is small, and further studies are needed to confirm our findings.