Robbie Ettinger (California) will present on March 23 and his session is entitled "Indoor Air Background Concentration Trends" at the Petroleum Hydrocarbon Vapor Intrusion I session.
Indoor air sampling is becoming a more common component of vapor intrusion investigations, yet resolving background contributions to indoor air quality continues to be a challenge in interpreting the results. Various techniques have been proposed to evaluate the contribution of background sources to indoor air concentrations; however, an understanding of typical (background) indoor and outdoor air concentrations of volatile organic compounds provides a baseline to quickly assess many problems. Many literature surveys on background indoor air quality are dated and the representativeness of these findings for current indoor air investigations has been questioned.
This paper reviews results from recent (i.e., after 2010) indoor air investigation studies and presents updated estimated background concentrations for volatile organic compounds typically detected in indoor air. Additionally, this paper will describe changes in the prevalence and/or concentrations of typical background constituents identified in earlier literature reviews. The implications of the temporal trends of background concentrations to future vapor intrusion investigations will also be discussed.