Fig. 1.

Field data from the U.S. EPA database. Subslab vapor concentrations divided by the paired exterior soil gas vapor concentration, plotted as a function of the ratio of the vertical distances to source of subslab and paired soil gas sampling points. l represents the vertical distance from subslab to vapor source, while l_sg represents the vertical distance from soil gas sampling point to source. All plotted concentrations are above the reporting limits. A vapor intrusion schematic with parameters are shown.