Any renovation, repair, or painting (RRP) project in a pre-1978 home or building can easily create dangerous lead dust. EPA requires that RRP projects that disturb lead-based paint in homes, child care facilities and preschools built before 1978 be performed by lead-safe certified contractors. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.