Final answer:
Lead-based paint was prohibited from being used after 1978 due to its health hazards and the risk of lead poisoning. The ban aimed to create safer living environments, especially for children.
Step-by-step explanation:
Lead-based paint was prohibited from being used after 1978. Prior to the ban, lead-based paint was commonly used in residential buildings. The U.S. government banned the use of lead-based paint due to its health hazards, especially for children who can be exposed to lead dust when the paint deteriorates or during renovations. The ban was implemented to reduce lead poisoning cases and create safer living environments.