Vapor intrusion occurs due to the migration of vapor-forming chemicals from any subsurface source into an overlying building.
Petroleum Vapor Intrusion (PVI-1)
Section 2 (Introduction)
VI occurs when vapors from contaminated groundwater or other subsurface sources migrate upward through vadose zone soils and into overlying buildings.
Vapor Intrusion (VI-1)
Section 1.6.3 (Preferential Pathways)
Discussion about vapor intrusion pathways and the permeability of subsurface materials.