Lead poisoning occurs when excessive levels of lead accumulate in the body, which can result in serious illnesses or even death. It is particularly dangerous in children and infants and is highly detrimental to physical and mental development. Figures from the CDC suggest around half a million children in the United States have high levels of lead in their blood. 

Lead is a highly dangerous contaminant and may adversely affect almost any organ or system in the body. The main source of lead poisoning is exposure to lead-based paint, but other sources include some cosmetics, contaminated soil, contaminated household dust, and certain occupations where lead is used, such as auto-repair and construction. 

Some symptoms of lead poisoning in children are problems or delays in development, learning difficulties, loss of appetite, fatigue, abdominal pain, hearing loss, diarrhea, constipation, irritability, and seizures. Signs in adults include high blood pressure, joint and muscle pain, abdominal pain, mood disorders, headaches, problems concentrating, low sperm count in men, and miscarriage, stillbirth or premature birth in pregnant women. 

Treatment of lead poisoning usually involves identifying and avoiding further exposure to lead, and in severe cases of poisoning, medication such as Chemet may be used to bind to the lead.