Lead poisoning occurs when a person swallows or inhales lead in any form, damaging the brain, nerves, and many other parts of the body. Acute lead poisoning, which is relatively rare, occurs when a large amount of lead is taken into the body all at once. Chronic lead poisoning, which is a common problem in children, occurs when small amounts of lead are taken in over a longer period.

Lead can damage almost every system in the human body, and it can also cause high blood pressure. It is particularly harmful to the developing brain of unborn babies and young children. The higher the level of lead in a child's body, the more serious the problems, which can include slowed reflexes, learning problems and even mental retardation. At very high levels, lead poisoning can cause seizures, coma, and death.

About one out of every six children...