Trends of Blood Cadmium Concentration Among Workers and Non-Workers in the United States (NHANES 2003 to 2012).

OBJECTIVE:We aimed to explore the trends of blood cadmium (bCd) concentrations among workers and non-workers in the United States. METHODS:We used serial cross-sectional data from the National Health and Nutrition Examination Survey (NHANES) (2003 to 2012), including 23,243 subjects aged 20 and above. We used linear regression to analyze the trends of bCd levels adjusting for demographic variables and smoking status, stratified by occupations. RESULTS:The geometric mean of bCd levels was 0.362 μg/L. Only 0.21% had elevated bCd concentrations (≥5 μg/L). Women, older age, ethnic minorities, people of lower socio economic status (SES), current smokers, blue-collars, and non-workers tended to have higher bCd levels. The bCd concentrations were stable through years in workers (n = 12,787), but had a decline from 0.532 to 0.476 μg/L (P-trend = 0.006) in non-workers (n = 10,456). CONCLUSIONS:Cd exposure in the United States has been controlled to a safe level. Special protective measures should be taken for the lower SES group and blue-collars.