1. Shannon Limjuco, Peter Corcoran, Trisha Calabrese, Cassandra Bernardi, and Alyse Plattos are with the American Academy of Pediatrics, Itasca, IL. Tanya Telfair LeBlanc is with the Lead Poisoning Prevention and Surveillance Branch, Centers for Disease Control and Prevention (CDC), Atlanta, GA, and is also a guest editor for this supplement issue. Alan Woolf is with the Harvard Medical School, Boston, MA.