About Lead
Blood lead level measures exposure to lead — a potent neurotoxin with no safe threshold that accumulates in the body over decades, stored in bones and slowly rereleased into blood. Even levels once considered 'normal' (5–10 mcg/dL) are now associated with reduced IQ, hypertension, kidney disease, and increased cardiovascular mortality in adults. Sources of exposure include old leaded paint (the most common), contaminated water (particularly from old pipes), occupational exposure, and some traditional herbal remedies.