What is "soil vapor intrusion"?

Soil vapor intrusion refers specifically to the process by which vapor-phase contaminants located in the subsurface, such as volatile organic compounds (VOCs), migrate through soil and ultimately enter nearby indoor air spaces. This phenomenon is of significant concern in environmental assessments and public health, as it can lead to exposure to harmful chemicals indoors when they move from contaminated soil or groundwater.

Understanding this process is critical when addressing environmental contamination, especially in urban areas where underground storage tanks (USTs) may leak harmful substances. By recognizing the contaminants and their potential pathways into buildings, professionals can take appropriate actions to mitigate risks and protect human health.

The other options do not accurately describe soil vapor intrusion. For example, groundwater contamination is a related issue but distinct from the specific movement of vapor into indoor spaces. Similarly, while the migration of air pollutants into the soil may occur, it does not encompass the full process of vapor phase contaminants affecting indoor air quality. Lastly, assessing UST conditions is a method related to the overall management of these systems but does not directly describe the phenomenon of vapor intrusion itself.