Blood Lead Below 0.48 (cid:1) mol/L (10 (cid:1) g/dL) and Mortality Among US Adults

Background —Blood lead levels above 0.48 (cid:1) mol/L (10 (cid:1) g/dL) in adults have been associated with increased risk of cardiovascular, cancer, and all-cause mortality. The objective of the present study was to determine the association between blood lead levels below 0.48 (cid:1) mol/L and mortality in the general US population. Methods and Results —Blood lead levels were measured in a nationally representative sample of 13 946 adult participants of the Third National Health and Nutrition Examination Survey recruited in 1988 to 1994 and followed up for up to 12 years for all-cause and cause-specific mortality. The geometric mean blood lead level in study participants was 0.12 (cid:1) mol/L (2.58 (cid:1) g/dL). After multivariate adjustment, the hazard ratios (95% CI) for comparisons of participants in the highest tertile of blood lead ( (cid:2) 0.17 (cid:1) mol/L [ (cid:2) 3.62 (cid:1) g/dL]) with those in the lowest tertile ( (cid:1) 0.09 (cid:1) mol/L [ (cid:1) 1.94 (cid:1) g/dL]) were 1.25 (1.04 to 1.51; P trend across tertiles (cid:2) 0.002) for all-cause mortality and 1.55 (1.08 to 2.24; P trend across tertiles (cid:2) 0.003) for cardiovascular mortality. Blood lead level was significantly associated with both myocardial infarction and stroke mortality, and the association was evident at levels (cid:3) 0.10 (cid:1) mol/L ( (cid:2) 2 (cid:1) g/dL). There was no association between blood lead and cancer mortality in this range of exposure. association between blood lead levels and increased all-cause and cardiovascular mortality was observed at substantially lower blood lead levels than previously reported. Despite the marked decrease in blood lead levels over the past 3 decades, environmental lead exposures remain a significant determinant of cardiovascular mortality in the general population, constituting a major public health problem. ( Circulation . 2006;114:1388-1394.) above 0.48 (cid:1) mol/L (10 (cid:1) g/dL) and cardiovascular, cancer, and all-cause mortality. these findings are substantial. The health effects of current lead levels on adult populations, however, are not viewed as a pressing public health concern. The present study, in conjunction with previous data, indicates that this perception may not be justified and that the current regulations for acceptable blood lead levels in adults are now outdated and may need to be revised. Because of the limited ability the present study had to evaluate the risks of lead exposure associated with blood lead levels below 0.10 (cid:1) mol/L (2 (cid:1) g/dL), there is a need for future research to identify the level of lead exposure that is no longer associated with adverse health outcomes. Although markedly reduced, current blood lead levels may not be low enough; practicable and cost-effective methods for reducing lead exposure in the general US population are needed.