Lead poisoning happens when lead builds up in the body, often over a period of months or years.Lead-based paint and lead-contaminated dust in older buildings are the most common sources of lead poisoning in children.At very high levels, lead poisoning can be fatal.Some of the signs and symptoms of lead poisoning in children may include: developmental delay, learning difficulties, and irritability.Listen in as Abby Markham, MD discusses lead poisoning, what to look for and possible treatments.