Dr. Sievert again...all around us:
Confluences, confluences. Today was the last flight of the Concorde, and they flew on a day where a solar mass coronal ejection was raining down on us.
I found a nice SIEVERT calculator for the radiation dose received during flights (click on the Union Jack for English...). You choose the departure and arrival cities, date and time, and what type of plane is used.
The following are temporary estimates, particularly since it's actually a pretty good solar flare going at the moment. Validated doses will be available on the SIEVERT site next month, and they will probably increase, despite the fact that a lot of jets avoided northern routes today because of the solar flare.
0.025 mSv from the last Concorde flight (3:15 elapsed) JFK to LHR, compared to
0.036 mSv from a subsonic flight (7:00 elapsed)
0.038 mSv from a business jet flight (6:00 elapsed)
Radiation exposure at flight altitudes is 100 to 300 times that at sea level, depending on the exact flight level and the solar weather.
Note that even though the rate of exposure on the Concorde was about twice as high because of the extreme altitude, the fact that the flight takes about half as long compensates. This also means that business jets have the highest rates of exposure, because they fly higher but can't reduce the exposure time enough to compare with commercial subsonic flights. Flight crews receive about 5 mSv/year from exposure.
Compare those doses to 0.66 mSv per day on the International Space Station, and with the 0.4 mSv/year we all receive from cosmic rays. Each average medical x-ray we get is about equivalent to one transcontinental subsonic flight.
If you happen to work in one of those charming old pink granite buildings, or in an area with lots of it as bedrock, you get the equivalent of one more chest x-ray/year from the potassium 40 in it.
And in some strange homeopathic news, apparently cells exposed to low levels of radiation can repair damage from extreme exposures more efficiently than those protected from any exposure at all.
So it's a good thing, right?