What type of abatement activity involves painting over a lead-based surface?

The correct answer is encapsulation, which refers to the process of coating a lead-based surface with a specialized encapsulating material, often paint that is designed to seal the lead and prevent the release of lead dust or particles. This method is intended to create a barrier, effectively containing lead, thus reducing the risk of exposure and health hazards associated with lead.

Encapsulation is typically used when the lead-based surface is in stable condition, and there is a need to prevent disturbance that could lead to lead exposure. It is a more cost-effective and less invasive approach than other methods, particularly in situations where the lead paint is not deteriorating or chipping away.

Other options do have their specific applications in lead abatement but are not appropriate for the description of painting over a lead-based surface. Sealing with wallpaper does not involve the use of paint or coatings specifically designed for encapsulation. Component removal entails taking out lead-containing materials entirely, which goes beyond simply covering them. Heat removal refers to a method that may involve the application of heat to remove lead-based paint but is not related to painting over surfaces.