Do you know what the ill effects of lead poisoning are? It can be very serious, ranging from neurological damage to birth defects, from kidney problems to brain damage. So you might wonder, why would anyone use that stuff for anything, and the answer is ignorance. When people first started using lead, they found it amazing how it could add vibrancy to colors, make it water-resistant, and how pipes made out of lead could be shaped so easily. Once the ill-effects were discovered, lead was banned from use, but that left a lot of homes out there with the deadly metal already in use.
How do you identify lead in your home? One way is by observing how your paint flakes. If it turns out to look like scales, it is most likely containing lead. If your pipes scratch easily, then they are probably made from lead.
You should be careful with cleaning up lead, since releasing it can be more harmful than leaving it alone. If you feel at all uncertain, you should get a professional to help you out.