Which of the following surfaces does NOT contribute to lead hazards?

Non-painted surfaces do not contribute to lead hazards primarily because they lack the inherent risk associated with lead-based paints. Lead hazards typically arise from painted surfaces, particularly those that are deteriorating or subject to friction, as these conditions can cause lead particles or dust to become airborne and accessible.

Impact surfaces, such as doors and windows that are frequently used, can also produce lead dust when lead-based paint rubs off due to contact. Deteriorated paint is a well-known source of lead exposure, particularly in older buildings where lead-based paints were commonly used. Friction surfaces are similarly hazardous, as they can create lead dust through wear and tear.

In contrast, non-painted surfaces do not contain lead as a component and therefore do not present the same risk, making them the correct choice in identifying a surface that does not contribute to lead hazards.