No amount of lead in the body is good. Exposure to lead in both large and small amounts can cause lead poisoning in adults and children. Once in the body, lead gets into the bloodstream and circulates to all of the organs in the body, such as the liver, kidneys, and the brain, where it does damage. Lead can interfere with how much the body absorbs iron, calcium, and other minerals that the body needs.

Exposure to a large amount of lead may require immediate attention. Consuming even a very small amount of dust with lead in it, over time, can also poison a child.

Lead dust can be created from opening and closing the doors or windows inside a home painted with lead-based paint. Lead dust may also result from other sources of deteriorating lead-based paint. A child is exposed to a very small amount of lead when he or she puts his or her mouth on toys covered with lead dust. Small doses of lead can build up in the bones and teeth, which can stay there for years. Sometimes this stored lead is released back into the bloodstream and circulates again to the organs in the body, which can harm growing organs, muscles, and bone and can slow a child's development.