Blood Lead Levels and Death from All Causes,Cardiovascular Disease,and Cancer:Results from the NHANES III Mortality Study

摘要

Analyses of mortality data for participants examined in 1976-1980 in the second National Health and Nutrition Examination Survey(NHANES II)suggested an increased risk of mortality at blood lead levels > 20 mu g/dL.Blood lead levels have decreased markedly since the late 1970s.In NHANES III,conducted during 1988-1994,few adults had levels > 20 mu g/dL.OBJECTIVE:Our objective in this study was to determine the risk of mortality in relation to lower blood lead levels observed for adult participants of NHANES III.METHODS:We analyzed mortality information for 9,757 participants who had a blood lead measurement and who were >= 40 years of age at the baseline examination.Using blood lead levels categorized as < 5,5 to < 10,and >= 10 mu g/dL,we determined the relative risk of mortality from all causes,cancer,and cardiovascular disease through Cox proportional hazard regression analysis.RESULTS:Using blood lead levels < 5 mu g/dL as the referent,we determined that the relative risk of mortality from all causes was 1.24 [95% confidence interval(CI),1.05-1.48] for those with blood levels of 5-9 mu g/dL and 1.59(95% CI,1.28-1.98)for those with blood levels > 10 mu g/dL(p for trend < 0.001).The magnitude of risk was similar for deaths due to cardiovascular disease and cancer,and tests for trend were statistically significant(p < 0.01)for both causes of death.CONCLUSION:In a nationally representative sample of the U.S.population,blood lead levels as low as 5-9 mu g/dL were associated with an increased risk of death from all causes,cardiovascular disease,and cancer.