Lead poisoning is the accumulation of lead in the body. Lead usually enters the body in the form of lead dust that is breathed in or by eating something that has been contaminated with lead. Children under 6 years old absorb lead more easily and are more easily harmed by lead.
Lead poisoning can happen slowly over time as lead builds up in the body or can happen suddenly if someone is exposed to a lot of lead at once. Most children who have lead poisoning do not look or act sick. The only way to know if someone has lead poisoning is by getting a blood lead test.
There is no known "safe" level of lead to have in the body. Any measurable amount of lead in the body may have negative health effects and can cause lifelong learning and behavior problems. The Centers for Disease Control and Prevention currently uses a reference level of 5 micrograms per deciliter (5 mcg/dL) or higher to identify children who have an elevated blood lead level.
Lead poisoning can be treated but most of the damage caused by lead poisoning is permanent. The good news is that lead poisoning is preventable.