Vapor Intrusion Simulations and Risk Assessments

Prof. Yijun Yao is a professor at the Institute of Soil Science, Chinese Academy of Sciences. His major research interest involves site investigation, risk assessments and management of soil pollution. He is the author of several risk assessment tools, including the CVI2D and PVI2D toolkits, and Yao’s spreadsheet for risk assessments for contaminated sites. He graduated from Brown University with a Ph.D. degree in Environmental Engineering in 2012. Prof. Qiang Chen is an assistant researcher in Nanjing Institute of Environmental Sciences of the Ministry of Ecology and Environment, with a research focus on investigation and risk assessment of contaminated sites, environmental policy and decision making, and software development. He has a master’s degree in Environmental Engineering from Hohai University and is now pursuing a doctoral degree under the supervision of Prof. Yijun Yao.

lt;p>Chapter 1 Introduction of the concepts and history of vapor intrusion (VI)

Author: Yijun Yao

This chapter gives the readers the basic idea about VI. We are planning to introduce the concepts, history, and framework of risk assessments in VI investigations.

Chapter 2 Statistical analysis of USEPA's VI database

Author: Yijun Yao

This chapter introduces the development of USEPA's VI database, and the use of it in determining generic attenuation factors. The limits of the database and improvements to generate more realist generic attenuation factors are also discussed.

Chapter 3 Statistical analysis of USEPA's PVI database

Author: Yijun Yao

This chapter introduces the development of USEPA's PVI database, and the use of it in obtaining vertical screening distances for PVI. Numerical simulations are also involved to justify the developed screening distances for NAPL and dissolved-phase sources of traditional petroleum products.

Chapter 4 Screening models of vapor intrusion (VI)

Author: Iason Verginelli

This chapter summarizes existing analytical models of vapor intrusion, and discusses the limits of current screening tools commonly used in this field, and the future research to improve them.

Chapter 5 Numerical models of vapor intrusion

Author: Iason Verginelli

This chapter summarizes the current numerical models of vapour intrusion and their use in simulating multiple dimensional scenarios of vapor intrusion and petroleum vapour intrusion.

Chapter 6 Alternative VI pathways

Author: Yijun Yao

This chapter introduces alternative VI pathways, that connecting subsurface vapour sources with subfoundation zone or indoor air, and discusses the scenarios in which it may play an important role in determining indoor air concentration.

Chapter 7 PVI involving High-Ethanol Blend

Author: Jie, Ma

This chapter discusses the possible hazards caused by vapor intrusion form a subsurface source involving high-ethanol blend, a kind of biofuel currently used. The investigations are involving a pilot-scale experiment, analytical calculations, and numerical modelling.

Chapter 8 Field practice to assess VI risks at developed sites

Author: Eric Suuberg

This chapter introduces the characterizations of soil vapour intrusion at a developed site, based on a technique of multiple lines of evidences, which includes groundwater sampling, subslab soil gas samples, exterior soil gas samples and indoor air samples, as well as screening model calculations.

Chapter 9 Field practice to assess VI risks in brownfield redevelopment

Author: Tao Long

The chapter introduces the practical methods to characterize soil vapor intrusion in a brownfield redevelopment case, with a purpose to determine the remediation criteria of soil/groundwater pollution. This chapter also includes an example where chlorinated solvents are involved due to the production of pesticides.