Lead is a toxic heavy metal found naturally in the environment and used in some products. It can harm humans and animals if ingested or inhaled. Children are especially vulnerable to lead toxicity, which can lower IQ and cause learning and behavioral problems. Pregnant women are also at risk because lead exposure can harm fetal development. Common sources of lead exposure include lead-based paint, contaminated soil, water pipes, and some folk remedies. Symptoms range from abdominal pain and fatigue at low levels to seizures and coma at very high levels. Treatment involves chelation therapy or surgery to remove lead from the body.