What to know
Vapor intrusion is when contaminated shallow groundwater can evaporate and move upward through the ground surface into indoor air of overlying or nearby buildings.
About vapor intrusion
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ATSDR identified about 23,000 historical documents containing data of interest.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?
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.
Findings
To date, ATSDR has completed an initial evaluation of 77 buildings and conducted preliminary health assessments for 39 of the 51 buildings with sufficient indoor air data. These evaluations have informed the development of preliminary recommendations, which are now available, below.
Importantly, based on our review of indoor air data from the most recent time period evaluated (typically 2010 to 2021), ATSDR has not identified any current public health hazards and does not anticipate ongoing exposures at levels of concern.
ATSDR is currently taking a strategic pause in this assessment. This will allow the agency to align the right personnel and expertise needed to complete the effort effectively.
ATSDR Preliminary Vapor Intrusion Recommendations
Building Area and Number
ATSDR Preliminary Vapor Intrusion (VI) Recommendation
HPIA: 902, 1005, 1068, 1101
OBA: LCH4007, LCH4014
Collect VI data (e.g., concurrent indoor air, subslab soil gas, and outdoor air canister samples) so that ATSDR can evaluate public health implications and validate vapor intrusion mitigation systems (VIMS).
Camp Geiger: G480, G532, G533, TC942
MCASNR: AS510, AS518, AS3905
Tarawa Terrace: TT19, TT2478
Monitor groundwater contaminant concentrations over time and collect VI data so that ATSDR can evaluate public health implications based on the VI evaluations.
Camp Geiger: G484, G531, G534, G560, G773
HPIA: 901, 903
MCASNR: AS143, AS427, AS480, AS502, AS515, AS516, AS541, AS831, AS843, AS4106, AS4151, TC1500
Tarawa Terrace: TT2477, TT5428, TT5430, TT5447, TT5704
OBA: A47, BB118, LCH4025
Sample groundwater and, if necessary, collect VI data so that ATSDR can evaluate public health implications based on the VI evaluations.
Camp Geiger: G531, G534
HPIA: 901, 902, 903, 1005, 1068
MCASNR: AS143, AS424, AS427, AS502, AS510, AS515, AS516, AS518, AS541, AS831, AS843, AS3905, AS4151
Tarawa Terrace: TT19, TT2457, TT2461, TT2467, TT2469, TT2471, TT2478
OBA: A47, LCH4007, LCH4014, LCH4025
Investigate potential preferential pathways from underground utility lines which appear to intersect groundwater contaminant plumes and connect to buildings.
Camp Geiger: G480, G533
HPIA: 901, 902, 903, 1005
Investigate indoor use of volatile organic compound (VOC)-containing products so that ATSDR can provide health education to minimize exposures to VOCs.
HPIA = Hadnot Point Industrial Area; MCASNR = Marine Corps Air Station New River; OBA = Other Base Areas
For more information on ATSDR's research on health risks related to Camp Lejeune, please visit the ATSDR Camp Lejeune website.