National estimates of blood lead, cadmium, and mercury levels in the Korean general adult population

Objectives To assess the extent of exposure to lead, cadmium, and mercury in the Korean general adult population using a representative sample. Methods We studied blood concentrations of three heavy metals in a representative sample of 1,997 Koreans as part of the Third Korean National Health and Nutrition Examination Survey (KNHANES III) performed in 2005. Results The geometric means of the blood lead, cadmium, and mercury concentrations were 2.61 mu g/dL, 1.53 mu g/L, and 4.15 mu g/L, respectively [95% confidence intervals (CIs), 2.50-2.71, 1.48-1.58, and 3.94-4.36, respectively]. Women had significantly lower blood lead and mercury concentrations in adjusted and unadjusted analyses but no difference between genders was observed in blood cadmium analysis. The geometric means of blood lead and mercury levels were higher in subjects older than 40 years than in those younger than 40 years. Smoking status only affected the blood lead concentration, with this being higher in smokers than in nonsmokers. Blood cadmium levels did not differ with demographic and lifestyle variables after covariate adjustment. Blood mercury concentrations were higher in those who consumed alcohol and also increased with the frequency of fish consumption. Conclusions This biomonitoring study of blood heavy metals in the Korean general population as part of KNHANES III provides important reference data stratified by demographic and lifestyle factors that will be useful for the ongoing surveillance of environmental exposure of the Korean general population to heavy metals.