Real Time Chemical Screening
Yes Virginia, there really is Chemical Screening Of Residences Using Real Time Instruments
And yes, we use those instruments.
Portable electronic instruments are available which can measure low levels of various toxic gases. These instruments can measure toxic gases at "parts per billion" (ppb) levels in a matter of minutes. Instruments are available for such gases as benzene and formaldehyde.
These instruments allow the testing of several locations in a home within an hour, at a cost of a few hundred dollars. A trained inspector can sample several rooms of a house, allowing a search for the most impacted area, in a short time and at low cost. This "screening" approach enables one to test tens or hundreds of homes to find which are affected by contamination. Each instrument tests for only one or two target chemicals.
An alternative approach, using a Summa canister, takes hours to perform, days to get results, and costs hundreds of dollars for each reading. And only one location can be done per house without prohibitive cost. The Summa canister test identifies hundreds of compounds in a shotgun approach.
Due to being more precise, and more legally defensible, Summa canister tests can be performed subsequent to the screening with an instrument. The screening provides target homes and locations to test with the canister, increases the potential for finding positive results, and reduces testing of unaffected homes with the more expensive methodology.