In 1996, federal law requires that individuals receive a Lead Paint Pamphlet and Disclosure Form before renting, buying, or renovating pre-1978 housing. Many houses and apartments built before 1978 have paint that contains lead (called lead-based paint). Lead from paint, chips, and dust can pose serious health hazards if not taken care of properly, which is one of the reasons why the requred documents must be given to residents.
For a free copy of the EPA info on lead paint hazards: Attach:epa_lead.pdf