Researchers from the Harvard School of Public Health (HSPH) and the University of Michigan School of Public Health found that bone lead was associated with a higher risk of death from all causes, particularly from cardiovascular disease.
"The findings with bone lead are dramatic," said Marc Weisskopf, assistant professor of environmental and occupational epidemiology at HSPH and lead author of the study.
"It is the first time we have had a biomarker of cumulative exposure to lead and the strong findings suggest that, even in an era when current exposures are low, past exposures to lead represent an important predictor of cardiovascular death, with important public health implications worldwide," he added.
During the study, the researchers examined 868 participants in the Department of Veterans Affairs Normative Aging Study, a study of aging in men that began in 1963. Blood lead and bone lead were analyzed using X-ray fluorescence.
The results showed that the risk of death from cardiovascular disease was almost six times higher in men with the highest levels of bone lead compared to men with the lowest levels.
The risk of death from all causes was 2.5 times higher in men with the highest levels of lead compared to those with the lowest levels.
According to the authors, there are a number of mechanisms, such as increased oxidative stress, by which lead exposure may result in cardiovascular mortality.
They also note that, in addition to high blood pressure, exposure to lead has been associated with widened pulse-pressure (an indicator of arterial stiffening) and heart disease.
Given that bone lead may be a better biomarker of cumulative lead exposure than blood lead, it may be the best predictor of chronic disease from exposure to lead in the environment.
The study appears in journal Circulation. (ANI)