Vapor intrusion is the migration of volatile chemicals from the subsurface into overlying buildings, one of the major causes for a large population exposure to hazardous chemicals. These volatile chemicals are often the result of buried waste and/or contaminated groundwater that can emit vapors that may migrate through subsurface soils and into indoor air spaces of overlying buildings. In extreme cases, the vapors may accumulate in dwellings or occupied building to levels that may pose near-term safety hazards (e.g., explosion), acute/chronic health effects, or aesthetic problems. According to a recent report, the two chlorinated chemicals that pose the highest risks from vapor intrusion are the ones that are most frequently found at contaminated sites.2 The two chlorinated compounds trichloroethylene (TCE) and perchloroethylene (PCE) are commonly found as soil or ground-water contamination. Though they exist as liquids under normal conditions, they may migrate upward as vapor intrusion from the ground into buildings. The effect of PCE and TCE on human health depend greatly on how much one is exposed to, and the length and frequency of exposure. Breathing small amounts of TCE may cause headaches, lung irritation, dizziness, and poor concentration.3 Animal studies have shown that long-term exposure to PCE and TCE is connected to kidney and liver damage. Other studies have shown an association between PCE and TCE exposure and cancer.4 Precise measurements of human exposure to chemical and biological agents that may lead to disease or dysfunction will facilitate development of remedy for it. Currently the indoor air monitoring for vapor intrusion is performed with summa canisters or Tedlar bags, both of which collect an air sample that must be analyzed off- site. Another method uses EPA's Trace Atmospheric Gas Analyzer, which gives real-time indoor air readings but is so large it is contained in a specialized bus. Both types of indoor air vapor intrusion analyses are time- consuming and costly, and require multiple entries into a residence. Thus, there is need for a real-time, hand- held, direct-reading air monitoring device that can detect vapor intrusion at trace levels. To address the need, Lynntech proposes to develop a compact, light weight and easy to operate vapor intrusion monitor capable of providing rapid test results. The proposed technology combines: i) solid phase extraction for selective capture and pre-concentration of VOCs, and ii) IR fingerprinting for the unambiguous identification of the analytes. The device can be used both inside and outside of a building to monitor volatile and semi-volatile toxic chemicals such as: TCE, PCE, polycyclic aromatic hydrocarbons and polybrominated diphenyls.
Vapor intrusion is the migration of volatile chemicals from the subsurface into overlying buildings;one of the major causes for a large population exposure to hazardous chemicals. In extreme cases, the vapors may accumulate in dwellings or occupied buildings to levels that may pose near-term safety hazards (e.g., explosion), acute/chronic health effects, or aesthetic problems. Lynntech is proposing to develop a field deployable vapor intrusion monitor capable of providing rapid test results based on solid phase extraction for selective capture and pre-concentration, and IR fingerprinting for the unambiguous identification of the analytes.
