Lead is a heavy metal fount in some paints, although it has lost popularity due to its toxicity it is still used for many industrial and military paint jobs as well as sometimes being used to paint roadways and parking area lines. Lead poisoning can cause nervous system damage, hearing loss, stunted growth, delayed development and kidney damage. The main cause of this poisoning is through the deterioration of paint causing dust which is then ingested by inadvertent hand to mouth contact. This is why it is very important to have the condition monitored of your lead based paint.