According to the Centers for Disease Control, lead poisoning is the number one environmental hazard to children AND the most preventable. In fact the only cure for lead poisoning is prevention. The dust becomes airborne, settles on floors and surfaces which children come in contact with. Friction areas such as windows create additional dust hazards.
Deposits gather in the window well, trough or on the window sill.
If a child comes in contact with these areas, there is the potential for lead poisoning by normal hand to mouth activity. The body mistakes lead for calcium when ingested. The lead then attaches to and disrupts enzymes essential to the functioning of the brain and other cells. The body never decomposes the lead into another, more easily tolerated substance, because lead is an element. The process of chelation can remove lead from the bloodstream, but most of the lead that is absorbed into a child's brain remains there forever.