Amount of I-131 underestimated by a factor of ten due the filter inefficiency?
I think your data might have underestimated the concentration of I-131 by a factor of 10, due to the inefficiency of the filter, as opposed to charcoal filled cartridge.
Here is the data released by the EPA on 3-28:
In it you can find that the charcoal filled cartridge is 10x more sensitive than air filter.
According to their data:
San Bernadino, CA 3/22/2011 0.11 pCi/m3 -- Filter
San Bernardino, CA 3/22/2011 1.1 pCi/m3 -- Charcoal Cartridge.
According to your data:
Berkeley, CA 3/22/2011, 2.25E-06 Bq/L, which is 0.06 pCi/m3.
So your data is on par with their filter data, and drastically lower than the charcoal cartridge data.
Also, data from a Las Vegas team (see prior forum posts with Las Vegas in title) who uses cartridge also show a 5 fold higher readings than what we get here in the bay area.
Thank you for considering this info, and please take a look to see if it is necessary to revise your dose comparison to reflect this change in 10 fold more cross country flights, and 10 fold less days of breathing the air, etc.
Thanks for keeping us informed.