Among the following, which is NOT a common area to find lead?

The option that is not a common area to find lead is floors. In lead hazard assessments, common areas where lead is typically found include casings, sills, and aprons (such as window aprons). These areas are often at risk because they can have lead-based paint that deteriorates over time, leading to lead dust and paint chips that can pose health risks, especially to children.

Floors, while they can also have lead-containing dust, are generally not classified as the primary locations for lead exposure in the same way that sills, casings, and aprons are, which see more direct abrasion and deterioration from usage, thereby releasing lead particles more readily into the environment. Hence, while lead may be present in older floors due to issues like lead paint, it is less likely to be a direct point of concern in a standard assessment compared to the other listed areas.