DNA methylation biomarkers for cumulative lead exposures and cognitive impairment.

Background: Recent evidence suggests that cumulative low-level lead exposure has adverse effects on cognitive function in the elderly. To date, the few studies that have measured bone lead exposure relied on K-X-ray fluorescence (KXRF), methods that are mostly unavailable in large community-based studies. Here, we employ a methylation-based estimation method for bone and blood lead in the Alzheimer's Disease Neuroimaging Initiative (ADNI) cohort.