The most common source of lead comes from paint used in buildings constructed before 1977. The older the building, the more likely lead-based paint was used during the initial construction. For example, homes built before 1940 are 87% likely to contain lead, while structures built between 1940 and 1959 are 69% likely to contain lead, according to the EPA. The percentage drops to 24% in homes built between 1960 and 1977. Lead-based paint may be found on: Walls Doors Window sills and structures Cabinets Ceilings Siding Metal components   The federal government banned consumer use of lead-based paint in 1978. Around 24 million homes still contain lead-based paint with elevated levels of lead-contaminated house dust. Older commercial buildings may have lead in pipes, faucets, and solder because it was a common construction material for pipes up until 1986 when Congress amended the Safe Drinking Water Act.  More than 99% of all publicly supplied water contains less than 0.005 parts per million parts of lead.  But this doesn’t account for lead pipes in older buildings that take in water from municipal pipes. Lead abatement companies are most concerned with the paint and pipes in older buildings when it comes to removing this hazardous material.