The adverse impact of lead upon the neurological functioning of children has been noted in many prior posts. A good review of the toxicological impact on children of lead can be found in the reports noted at http://www.atsdr.cdc.gov/ToxProfiles/tp.asp?id=96&tid=22. However, less well known is the growing awareness of the impact of low lead levels on adults.
Researchers have noted that there has been a dearth of studies regarding low levels of lead in adults and cardiovascular impacts. Thus, the researchers assessed blood lead and bone lead (seen as a biomarker of cumulative lead exposure) and electrocardiographic test results over time. The researchers found that people with the most lead in their bones could be at elevated risk of developing "perturbed electrical cycles" in the heart, as measured by electrocardiograms. [For a less than ideal (but still informative) discussion of electrical conduction in the heart, see http://en.wikipedia.org/wiki/Electrical_conduction_system_of_the_heart.]
The body treats lead as it does calcium, storing much of the toxic metal in bones. The electrical changes emerged during an eight-year study of roughly 500 otherwise healthy elderly Boston-area men and occurred in the men with the highest lead levels (likely due to exposures from dust and tainted water). Although the mechanism is unknown, lead has been associated with elevated blood pressure and may increase the resistance of blood flow through vessels. Such changes could signal individuals at risk for sudden death, the researchers report.
The study can be found at http://ehp03.niehs.nih.gov/article/fetchArticle.action?articleURI=info%3Adoi%2F10.1289%2Fehp.1003279.