Is My Drywall Chinese? - HB Litigation Conferences

Conc. (ppmv)
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
Implications of Tedlar Bag Use
Loss of H2S in Saturated Humidityy
Excess Water Dry
0.0
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
Time (minutes)
Laboratory Data (ppmv)
Field vs. Laboratory Analysis
0.001 0.01 0.1 1 10
Jerome Data (ppmv)
Rapid losses of analyte over time Low bias
Static Headspace Analysis
• Concentrations measured cannot be easily related to indoor air concentrations
Concentrations measured cannot be easily related to indoor air concentrations
• Useful for ranking source material only; cannot be used for source strength
assessment, e.g., total emissions into home.
• Accuracy of H2S is questionable
• H2O diffuses through bag
10
1
0.1
0.01
0.001
6/23/2009
8