Lead-based paint was used in many houses built before 1978. Paint chips, found both inside and outside of the house, can be all too easily ingested by children. The soil around a dwelling can also pick up lead from exterior paint or residue from leaded gas that was once used in cars. Children can swallow or inhale lead dust by playing in or near soil around the yard. When this soil is tracked into the house, it becomes part of household dust, along with deteriorating lead-based paint found indoors.