Serum Heavy Metals and Obstructive Lung Disease: Results From the National Health and Nutrition Examination Survey

Background Exposure to hazardous heavy metals such as cadmium and lead has been associated with several chronic diseases. Heavy metal exposure may contribute to increased oxidative stress and inflammation in the lungs, resulting in tissue destruction manifesting clinically as obstructive lung disease (OLD). We aimed to evaluate the association between serum cadmium and lead concentration and OLD. Methods Pooled cross-sectional data from the National Health and Nutrition Examination Survey 2007-2010 were used. OLD was defined as an FEV 1 /FVC ratio Results The prevalence of OLD was 12.4% (95% CI, 10.2%-13.6%). The mean (SE) cadmium levels in the OLD group were significantly higher in comparison with normal control subjects (0.51 [1.04] vs 0.33 [1.02], P P 1 % predicted values among smokers in our study population. Conclusion In a large representative sample of the US population, we demonstrated a significant association between OLD and serum cadmium and lead concentrations. Cadmium appeared to partially mediate the association between smoking and OLD. A dose-response effect between increasing cadmium concentration and progressively worsening lung function was observed in smokers.