Vapor Intrusion Public Health Assessment
- What is vapor intrusion?
Volatile chemicals in contaminated shallow groundwater can evaporate and move upward through the ground surface into indoor air of overlying or nearby buildings—this process is called vapor intrusion (VI). Breathing indoor air contaminants in Marine Corps Base (MCB) Camp Lejeune’s buildings due to vapor intrusion is a potential pathway of exposure to shallow groundwater contaminants.
- What is the purpose of the vapor intrusion assessment?
The Vapor Intrusion Public Health Assessment (VI PHA) has two objectives:
- To evaluate whether people’s health might be harmed from current or past exposures to indoor air contamination that may have resulted from vapor intrusion into buildings on the base.
- To evaluate the effectiveness of current vapor intrusion systems designed to reduce indoor air contaminant amounts installed in some buildings on base.
- What data are ATSDR using in its evaluation?
ATSDR identified about 23,000 historical documents containing data of interest. The agency also identified electronic files containing environmental data from MCB Camp Lejeune and its contractors. Environmental data include indoor air, outdoor air, soil gas, soil boring, and shallow groundwater sampling data relevant to the VI evaluation. Building-specific information, such as use, occupancy, and construction information, are also key pieces of data considered in the evaluation.
- How many buildings are being evaluated?
At this time, ATSDR is evaluating about 150 buildings. Because the MCB Camp Lejeune is so large (approximately 14,000 buildings), ATSDR first conducted an evaluation of the whole base to prioritize buildings. We used various vapor intrusion factors during our evaluation to focus on buildings in areas of the base with the greatest concern for potential VI impacts. The agency will recommend public health actions if people’s heath has been or is being harmed from vapor intrusion.
- When will the evaluation results be available?
Vapor intrusion assessments of each of the 150 buildings are very complex. We expect to release the results of our assessments for public comment in early fall 2024. After we address public comments, we will release the final report.