Vapor Intrusion is the migration of volatile chemicals from the subsurface into overlying buildings. Volatile chemicals may include volatile organic compounds, select semi-volatile organic compounds, and some inorganic analytes, such as elemental mercury and hydrogen sulfide. Degradation of the indoor air quality causes a great deal of fear and anxiety among building occupants, business, and other property owners. Vapor intrusion has become a significant environmental issue for regulators, industry leaders, and concerned residents. Vapor intrusion requires three components: the source, an inhabited building, and a pathway from the source to the inhabitants.
The ITRC Vapor Intrusion Team is composed of representatives from 19 states environmental agencies, 12 environmental companies, and four federal agencies (including EPA). This team developed the ITRC Technical and Regulatory Guidance document Vapor Intrusion Pathway: A Practical Guideline (VI-1, 2007), companion document Vapor Intrusion Pathway: Investigative Approaches for Typical Scenarios (VI-1A, 2007), this Internet-based training course, and a two-day classroom training course to be used by regulatory agencies and practitioners alike. For more information about the in-depth classroom training course, please visit the ITRC Classroom Training webpage. This Internet-based training course provides an overview of the vapor intrusion pathway; summarizes introductory information on the framework (evaluation process), investigative tools, and mitigation approaches; and utilizes typical scenarios to illustrate the process.