Lead once was a component in many common materials such as interior and exterior paints, gasoline, and the solder used to bond copper and steel plumbing pipes to one another. The U.S. government banned lead in paint and solder in the 1970s, and phased out its use in gasoline during the 1980s. Even so, lead can still be found in some homes built before 1980 and in the soil around such older homes.

As a heavy metal, lead is difficult to flush out of the body once inhaled or ingested. Lead poisoning can strike people of any age, but the worst and most long-lasting effects of elevated lead levels in the blood occur in fetuses and children under age 6.

Old, peeling paint may be familiar to most people as the culprit in lead poisoning. These days, though, lead dust is a far bigger source of lead. The dust can be tracked into the house from contaminated soil or from certain workplaces. Some dust can be released from older painted surfaces in the home that get lots of use, such as windows and window sills, doors and door frames, stairs, railings and banisters, porches, and fences.

The only sure way to rid a home of lead permanently is to hire a lead-abatement contractor. Several steps can be taken to reduce the threat without having to resort to this costly step, as long as paint is not chipping, peeling, or subject to abrasion. Lead paint that is in good condition is not considered a health hazard.

• Wash window frames, windowsills, floors, baseboards, and other hard surfaces once a week, and rinse the cloths thoroughly afterward. All-purpose cleaners are sufficient for this task. Dedicate cleaning tools and supplies to this task to avoid spreading lead to other areas of the home.
  
  
• Remove shoes or use walk-off mats at entrances to keep lead from soil or other sources outside the home.
  
  
• Keep vacuum cleaners well maintained and change the dust bag (or empty the dust chamber — outdoors!) regularly. Use vacuums employing HEPA-type bags or filters to avoid releasing dust back into the home air.
  
  
• Consider planting grass or another ground-covering plants over suspect soils.

Reference:

U.S. Environmental Protection Agency lead information page