The cosmic-radiation field at FL390: explained, sourced, in plain English.
Ten reference guides on how much cosmic radiation a flight actually delivers, why latitude and altitude matter so much, what the relevant ICRP and FAA limits are, and how the numbers compare to things you already understand like a chest X-ray. Every guide cites FAA, ICRP, NCRP, NOAA or ACOG primary sources. Reviewed 24 May 2026.
FAA CARI-7 explained: how aircrew dose is actually calculated
The Monte Carlo transport code the FAA publishes for civil-aviation dosimetry: inputs, outputs, validation history, and how CARI-7 differs from CARI-6.
Polar routes and cosmic dose: why latitude matters
Why geomagnetic latitude above 60° drives a disproportionate share of transatlantic and transpolar dose. With a polar vs mid-latitude comparison table.
Solar particle events: when SPEs raise in-flight dose
How SPEs work, the NOAA S-scale, the historical record, and what the SPE contribution to lifetime dose really is for a typical flier.
Pregnancy and flying: ICRP and ACOG guidance compared
The ICRP-103 1 mSv fetus limit, the ACOG 656 50 mGy reference, and how each maps to occasional vs frequent flying. Sourced, no scaremongering.
Aircrew dose limits: the 20 mSv/yr ICRP rule explained
The ICRP-103 occupational limit, the FAA 6 mSv/yr action level, the EU EURATOM rules, and the difference between an action level and a regulatory cap.
Frequent-flyer dose math: when it actually starts to matter
What annual dose looks like at 50, 100, 200 and 400 hours of flying, and where the trip-count curve crosses each ICRP / FAA reference number.
Galactic cosmic rays vs solar radiation: the difference
Two distinct radiation environments at cruise altitude: different sources, different spectra, opposite reactions to the 11-year solar cycle.
Lower altitude = lower dose: how much it really helps
How dose rate scales with altitude between FL250 and FL410. With a per-flight-level dose-rate table from CARI-7A.
Flight dose vs medical imaging (CT, X-ray)
One transatlantic flight vs chest X-ray, head CT, low-dose lung CT, coronary calcium scan, and a year of natural background. Actual mSv numbers.
Flight attendants and cancer risk: what the studies actually show
The NIOSH Flight Attendant Health Study and related cohorts. The empirical evidence on cabin-crew cancer incidence, with the methodological caveats.
Want the number for your own flight?
The guides explain the physics and the limits. The PDF report runs CARI-7 on your actual flights and tells you what your annual dose is.
Get my flight dose · $9Reviewed 24 May 2026 · 10 guides · ~ 21,000 words