[chrischen]

I'm not sure that banana chart from wikipedia is up-to-date:

https://www.radiologyinfo.org/en/info.cfm?pg=safety-xray https://www.health.harvard.edu/cancer/radiation-risk-from-me...

Most sources seem to put it at 0.1 mSv for a chest x-ray.

The FAA link for a Tokyo to LA 9 hour flight would be about 0.0206 mSv, or approximately 2 chest x-rays for the total flight.

However the FAA research you linked would put a New York to Seattle flight at a total of 0.112 mSv, whereas this CDC link says a trans-continental flight is only at the order of mangnitude of 0.035 mSv...

https://hps.org/publicinformation/ate/faqs/commercialflights... - summarizes more sources that contradict the raw FAA numbers.

This FAA calculator also seems to give numbers that agree with the lower radiation levels: http://jag.cami.jccbi.gov/cariresults.asp