Depends on the actual scan. A head CT can be as little as one sievert while a full blown angiogramm can be more than ten sievert. A pilot can accrue 40k flight hours over his career. If 90% of that is at cruising altitude (meaning 3-6 microsievert/hour), that would be 100-200 mSv in total. That would be equivalent to more than a hundred head CTs or a dozen angios. If you need that many CTs, your lifetime cancer risk is probably your smallest concern. But you still wouldn't expose any normal human to that level of radiation.
For general comparison astronauts are exposed to approximately 72 millisieverts (mSv) while on six-month-duration missions to the International Space Station (ISS).
According to linear no-threshold model (LNT model) the incidence of cancers due to ionizing radiation can be modeled as increasing linearly with effective dose at a rate of 5.5% per sievert, so a flight crew member receiving 200 mSv lifetime dose should have 1.1 % higher lifetime chance of cancer then general population. LNT is quite good model for high doses, but there is much less confidence for LNT at low doses, there both studies which confirm LNT at low doses and reject LNT at low doses.
For the overall US population risk of developing any cancer is 39.9% for men, 39.0 % for women.
Cosmic radiation is mainly protons and heavier nuclei. It's called radiation for legacy reasons, but it's a different beast from Earth's medical CT scans and X-rays which are manly photons.
Cosmic radiation hitting planes is also not the original cosmic protons and He nucleus etc, but secondary N and O nucleus hit by Cosmic particles creating a shower of neutrons, secondary and gamma protons, muons, pions, nuclear fragments... There's also a high dose of photons from these collisions, but proportionally it can be 500x less photons than a CT scan for a 10h USA-Europe flight.
What's biologically significant for air crew are these secondary protons and neutrons, which punch above their weight in damage interactions, they are not comparable to X-rays in Sieve alone.
Wonderful work by Mr. XKCD (Randall Munroe).
This was published in 2011 when there was "some" misinformation in the U.S. press about the Fukushima nuclear accident.
Based on this chart some proposed to use "bananas" as unit of radition (equivalent to 0.1 uSv).
So (from this chart) one flight from New York to LA exposes you to 400 bananas worth of radiation.
Replacing X-Ray and CT with new imaging would reduce exposure.
HIFU ultrasound arrays are already approved.
Recent research here indicates that longitudinally-polarized Proca waves are usable for Angstrom-scale medical imaging and treatments including tumor lysis and DNA repair.
There are apparently ways to target cancerous cells by their bio signatures in order to only target non-benign tissues.
I'm happy that I kept on with this line of research long enough to realize the medical capabilities (and fire suppression) it enables;
Attendants have higher risk than pilots. This kind of makes sense, as my understanding is they don't have pilots fly too often. Meanwhile, attendants are flying all the time.
In my search, I found that they spend almost an equal number of hours in air like you said - 75-100 hours per month. If that's the case, after adjusting for sex, these numbers holding would throw some uncertainty into the radiation hypothesis.
It varies with the airline and their staffing needs and your seniority as well. Some might fly you to your legal limits and you might have to get a ride back home on top of that. Some you might be on call but never really called, and might not be formally scheduled for much, and therefore might only fly a couple times a month through some stretches.
Your comments makes problematic suggestions, but I found it funny that the more childish one —farts– is actually very true: with the lower pressure, people do fart more on airplanes.
According to Gemini, radiation related cancer rates aren't higher in high elevation cities like Quito or La Paz... Shouldn't they be too? Airliners fly a lot higher but people live in these 24x7.
High altitude Equatorial populations and air crew exposures are different beasts. A 10h flight close to the North Pole is like living in Quito for almost a month. The type of dosage (bursts x contínuous) also matters as the body can probably accommodate more easily, but that's just me saying. Then add natural selection to that mix that should have helped prepare high-altitude populations residents for those living conditions, which will heavily skew the data. Finally, the cosmic shower has lost a lot of energy from 12,000m to say 2,500m, so the "hit" is not the same. It all may end up having an exponential effect reducing cancer rates...
So a flight attendant that clocks ~700h a year, that's roughly 5 years of living in Quito in a year of flying in Sieves. Now, given that the air crew studies are not all that conclusive yet, take high-altitude populations at 5x less exposure and all these other factors I've mentioned, and they will end up having an even lower chance of showing up in any cancer studies.
This doesn't really say what it looks like it says.
They don't have an above average risk of dying of cancer. Rather, if they die they are more likely than average to have died of cancer.
Which is not exactly surprising given that the medical screenings remove many of those who would die of heart issues. What would be strange is if there wasn't a higher percentage of cancer deaths.
To illustrate, my numbers are not meant to be accurate. Population at large, 100 red marbles (heart), 80 black marbles (cancer), 80 blue marbles (everything else). Cancer is 80/260 of the total.
Medical checks, you removed 80 of those red marbles. Now you have cancer at 80/180 of the total.
The percentage of cancer went up. Did the total cancer? No.
Lead is bad because the high energy particles hitting lead can multiply particle count. You’d need a significant amount, like 25cm thickness. Too much for weight limits of any airplane.
Boeing, Bombardier, Learjet, Embraer and Airbus should be forced to clean up aircraft cabin air they poison us with.
For people who don’t know how GROSS this is: on almost every modern passenger jet, the air you breathe is pulled through the engine’s Bleed-Air system before entering the cabin. As oil, hydraulic fluid, or other contaminants leak into that system, those superheated fumes can be pumped directly into the cockpit and cabin. These incidents are literally called "fume events" and are the basis of the "gym sock" smell you can detect when in airports or on a plane, especially during takeoff and landing. This is so pervasive you'll see airline attendants spraying glycol-based air fresheners during these times to COVER UP the smell of this toxic stuff.
And no, the HEPA filter people like to point to does not make this problem disappear. HEPA filtration primarily cleans recirculated particles. It does not magically remove every gas, vapor, or contaminant entering through the aircraft’s air-supply system.
The absurd part is that we already know how to avoid this architecture. The Boeing 787 is the major commercial exception: its cabin air is supplied by dedicated electric compressors rather than engine bleed air.
So this is not some unsolved engineering problem. The industry made a DESIGN choice to KEEP using a system capable of feeding contaminated engine air into a sealed tube full of passengers, pilots, and flight attendants. Zero regard for their well-being in order to save a few pounds and eck-out more miles per gallon.
Flight crews spend thousands of hours breathing this air over their careers. Passengers have no meaningful ability to know when contamination occurs or opt out. Manufacturers and airlines alike are afraid to put contamination sensors on their planes because it exposes them to liability - it shows the true extent of the problem.
That is not an acceptable health standard in 2026, and it wasn't when these decisions were made. Fix the source, stop pretending filtration alone solves it, and make bleed-air-free cabin ventilation the standard for new aircraft. Demand this from your regulator or determine who is responsible for your health effects.
> This is so pervasive you'll see airline attendants spraying glycol-based air fresheners during these times to COVER UP the smell of this toxic stuff
I've never once seen a flight attendant do that. Flown hundreds and hundreds of times. You'd think something that's "so pervasive" would have been common enough that I'd have seen it dozens of times?
Feels like youre defensive about this would love to know why. If you havent seen aerosols on a flight youre being disengenous or are not looking up/around. They are used for lavoratories and pest fumiagation during passengered flights regularly - and those are uses we agreed to as a society. Ive seen firsthand them sprayed during takeoff and landing at the time fume events are most noticed by passengers.
Disclaimer: I am an aviation enthusiast and loves planes and their design. I am unaffiliated with any airline or manufacturer. I want everyone to breathe ok.
> These incidents are literally called "fume events"
Your first FAA link says that these 'fume events' are rare: "The report found that the rate of cabin air quality events is less than 33 events per million aircraft departures." This is about one event every 30,000 flights.
I have a pretty sensitive sense of smell, and I regularly smell oil/smoke/hydrocarbon smell after they're starting the engines. It also sticks on your clothes after the plane ride, and I'm quite sure it's not just stinky seat smell.
If you think of the last 10 flights you were on, how many had the gym sock smell? That's the real occurence rate. I'd say in my experience across all airlines its around 7/10 flights I can detect via smell a fume event.
Quite interesting. My reaction is that one of these is much more easily controlled and an input for cancer than the other. Radiation shielding is a tougher solve due to weight and other factors, where air quality is an easy, known fix.
Would love both to be solved, which would lead to good outcomes. Any thoughts on why attendants have different outcomes?
That's interesting to know (thanks for calling it out!), and makes me feel extra glad I've worn a mask during the entire flight on every flight I've been on since 2020 (not that I've been on many)... turns out I was avoiding a lot more than just COVID etc. heh >_<
I believe the pilots air source works differently than the rest of the cabin - at least on the 737. Maybe that explains the difference between the pilots and the flight attendants.
Recently designed a sustainable thermofluid that it says would work as hydraulic fluid and a de-icing fluid: LBGPC: Lignin, BioPG, Graphene, Phytic acid, Citric acid
Like others, I have zero experience with any of the things you are mentioning, but I want flying to be more expensive, more luxurious, and far more comfortable in general for everyone so please keep giving them a hard time about this.
In general, 50% or more of the people flying should not be flying, and going back to the pre-privatization era alongside much stricter regulations on seat sizes would be awesome as it would force actual economics of scale to kick in for the good seats and keep the burger king crown wearing crowd ( https://www.youtube.com/watch?v=onib3bDo6Z0 ) off these airplanes for good.
Feel free to pay extra for the fancy seats up front, known as either first class or business class depending on the airline you're flying (I've seen other names for them like "premier" or something, too). But if you keep up the "I know what's best for other people" attitude that you display in your second paragraph, don't be surprised if people start thinking... poorly of you. (I rewrote that sentence multiple times. That's the kindest way I can put it. A lot of my earlier drafts were... more unkind).
Cancer Flight attendants Pilots
------------------------------------------------------
All radiation-related 1.50x 1.36x
Breast cancer 1.61x 1.57x
CNS / brain cancer 1.51x 1.28x
Multiple myeloma 1.34x 1.08x
Leukemia 1.12x 1.27x
Lymphoma 1.19x 1.04x
Prostate cancer 1.75x 1.38x
Melanoma 1.63x 1.28x
Nonmelanoma skin cancer 1.50x 1.22x
Other cancers 1.21x 0.97x
It was a cross-sectional analysis of U.S. death certificates from
2020-2024, covering ~13 million deaths across 503 occupations,
including roughly 14,000 pilots and 7,000 flight attendants. The analysis adjusted for age at death, sex, race/ethnicity,
education, and marital status.
So in other words, breast cancer was the cause of death at a rate 61% higher for flight attendants than for the comparison population of other occupations.
I read once that a CT scan is roughly equivalent to 1000 hours of flight WRT radiation exposure. I've had about 6 or 8 of those over the years.
Depends on the actual scan. A head CT can be as little as one sievert while a full blown angiogramm can be more than ten sievert. A pilot can accrue 40k flight hours over his career. If 90% of that is at cruising altitude (meaning 3-6 microsievert/hour), that would be 100-200 mSv in total. That would be equivalent to more than a hundred head CTs or a dozen angios. If you need that many CTs, your lifetime cancer risk is probably your smallest concern. But you still wouldn't expose any normal human to that level of radiation.
Air crew radiation exposure depends strongly on cruising altitude and Latitude, for example flight Tokyo JP – New York NY is about 67 microsievert.
https://www2.ans.org/pubs/magazines/nn/docs/2000-1-3.pdf
For general comparison astronauts are exposed to approximately 72 millisieverts (mSv) while on six-month-duration missions to the International Space Station (ISS).
https://en.wikipedia.org/wiki/Effects_of_ionizing_radiation_...
According to linear no-threshold model (LNT model) the incidence of cancers due to ionizing radiation can be modeled as increasing linearly with effective dose at a rate of 5.5% per sievert, so a flight crew member receiving 200 mSv lifetime dose should have 1.1 % higher lifetime chance of cancer then general population. LNT is quite good model for high doses, but there is much less confidence for LNT at low doses, there both studies which confirm LNT at low doses and reject LNT at low doses.
For the overall US population risk of developing any cancer is 39.9% for men, 39.0 % for women.
https://www.cancer.org/cancer/risk-prevention/understanding-...
2 replies →
Cosmic radiation is mainly protons and heavier nuclei. It's called radiation for legacy reasons, but it's a different beast from Earth's medical CT scans and X-rays which are manly photons.
Cosmic radiation hitting planes is also not the original cosmic protons and He nucleus etc, but secondary N and O nucleus hit by Cosmic particles creating a shower of neutrons, secondary and gamma protons, muons, pions, nuclear fragments... There's also a high dose of photons from these collisions, but proportionally it can be 500x less photons than a CT scan for a 10h USA-Europe flight.
What's biologically significant for air crew are these secondary protons and neutrons, which punch above their weight in damage interactions, they are not comparable to X-rays in Sieve alone.
This chart has the flight & CT scan scenarios (among many other): https://xkcd.com/radiation/
WOW, what a cool chart! :)
Thanks for the link!
Didnt know that one Mammogram is that intensive, so my partner shouldnt go each year, Id guess?
Wonderful work by Mr. XKCD (Randall Munroe). This was published in 2011 when there was "some" misinformation in the U.S. press about the Fukushima nuclear accident.
Based on this chart some proposed to use "bananas" as unit of radition (equivalent to 0.1 uSv).
So (from this chart) one flight from New York to LA exposes you to 400 bananas worth of radiation.
1 reply →
When are you getting your captain stripes then?
Cancers rates among Orthopedic surgeons are also much higher than those faced by non surgeon doctors.
This is due to exposure to the radiation from intra operative x rays.
Replacing X-Ray and CT with new imaging would reduce exposure.
HIFU ultrasound arrays are already approved.
Recent research here indicates that longitudinally-polarized Proca waves are usable for Angstrom-scale medical imaging and treatments including tumor lysis and DNA repair.
There are apparently ways to target cancerous cells by their bio signatures in order to only target non-benign tissues.
I'm happy that I kept on with this line of research long enough to realize the medical capabilities (and fire suppression) it enables;
Public link: "I/Q Sampling for Signal Phase" https://share.gemini.google/rDVcVwDnWPTc
It's a Twistor-Grassmanian mapping?
Our company shared a wall with an xray lab next door. My coworkers and I were always curious what impacts it would have to our health.
Probably nothing if the wall was lead lined.
And then there’s the inverse square law too.
Attendants have higher risk than pilots. This kind of makes sense, as my understanding is they don't have pilots fly too often. Meanwhile, attendants are flying all the time.
> as my understanding is they don't have pilots fly too often
From a quick search, I can’t find evidence of this. If anything, pilots are in the air more of their week/lives vs. flight attendants.
In my search, I found that they spend almost an equal number of hours in air like you said - 75-100 hours per month. If that's the case, after adjusting for sex, these numbers holding would throw some uncertainty into the radiation hypothesis.
5 replies →
It varies with the airline and their staffing needs and your seniority as well. Some might fly you to your legal limits and you might have to get a ride back home on top of that. Some you might be on call but never really called, and might not be formally scheduled for much, and therefore might only fly a couple times a month through some stretches.
I guess I am going off when a pilot spoke at my high school for career day. (Decades ago...)
I wonder if pilots' medical checks would catch some of these early?
1 reply →
[flagged]
Your comments makes problematic suggestions, but I found it funny that the more childish one —farts– is actually very true: with the lower pressure, people do fart more on airplanes.
2 replies →
They are also more exposed industrial disinfectants and cleaners used to clean the cabin than are pilots.
[flagged]
3 replies →
[flagged]
According to Gemini, radiation related cancer rates aren't higher in high elevation cities like Quito or La Paz... Shouldn't they be too? Airliners fly a lot higher but people live in these 24x7.
High altitude Equatorial populations and air crew exposures are different beasts. A 10h flight close to the North Pole is like living in Quito for almost a month. The type of dosage (bursts x contínuous) also matters as the body can probably accommodate more easily, but that's just me saying. Then add natural selection to that mix that should have helped prepare high-altitude populations residents for those living conditions, which will heavily skew the data. Finally, the cosmic shower has lost a lot of energy from 12,000m to say 2,500m, so the "hit" is not the same. It all may end up having an exponential effect reducing cancer rates...
So a flight attendant that clocks ~700h a year, that's roughly 5 years of living in Quito in a year of flying in Sieves. Now, given that the air crew studies are not all that conclusive yet, take high-altitude populations at 5x less exposure and all these other factors I've mentioned, and they will end up having an even lower chance of showing up in any cancer studies.
So... not remotely comparable.
This doesn't really say what it looks like it says.
They don't have an above average risk of dying of cancer. Rather, if they die they are more likely than average to have died of cancer.
Which is not exactly surprising given that the medical screenings remove many of those who would die of heart issues. What would be strange is if there wasn't a higher percentage of cancer deaths.
… IF they die?
You do not understand what I'm saying.
To illustrate, my numbers are not meant to be accurate. Population at large, 100 red marbles (heart), 80 black marbles (cancer), 80 blue marbles (everything else). Cancer is 80/260 of the total.
Medical checks, you removed 80 of those red marbles. Now you have cancer at 80/180 of the total.
The percentage of cancer went up. Did the total cancer? No.
A water bladder above the cockpit might help? I'm not a nuclear physicist, but I stayed at a HolInn Express last night...
Don't forget your lead body armor when going on long flight trips (which they can't charge you extra for).
Not an auth wall.
Not a pay wall.
Not even a cookie wall (Block Element! bullet ricochet noise)
But a Terms of Use wall?
For an article?
I just wanna read it.
I've wondered if billionaires get their jets lined with lead.
Lead is notoriously heavy, but if you buy a 737 and it only ever has to fly you and a couple other people, it might be feasible.
Or I guess they could just line one section where they spend the majority of the time.
Lead is bad because the high energy particles hitting lead can multiply particle count. You’d need a significant amount, like 25cm thickness. Too much for weight limits of any airplane.
hmmm...
looks like there's something called ultra-high-molecular-weight polyethylene.
"UHMWPE/hydrogen-rich benzoxazine composite (UHC) exhibits excellent cosmic radiation shielding."
maybe that should be a thing.
Boeing, Bombardier, Learjet, Embraer and Airbus should be forced to clean up aircraft cabin air they poison us with.
For people who don’t know how GROSS this is: on almost every modern passenger jet, the air you breathe is pulled through the engine’s Bleed-Air system before entering the cabin. As oil, hydraulic fluid, or other contaminants leak into that system, those superheated fumes can be pumped directly into the cockpit and cabin. These incidents are literally called "fume events" and are the basis of the "gym sock" smell you can detect when in airports or on a plane, especially during takeoff and landing. This is so pervasive you'll see airline attendants spraying glycol-based air fresheners during these times to COVER UP the smell of this toxic stuff.
[FAA overview](https://www.faa.gov/newsroom/cabin-air-quality-0)
And no, the HEPA filter people like to point to does not make this problem disappear. HEPA filtration primarily cleans recirculated particles. It does not magically remove every gas, vapor, or contaminant entering through the aircraft’s air-supply system.
[FAA research](https://www.faa.gov/sites/faa.gov/files/data_research/resear...)
The absurd part is that we already know how to avoid this architecture. The Boeing 787 is the major commercial exception: its cabin air is supplied by dedicated electric compressors rather than engine bleed air.
So this is not some unsolved engineering problem. The industry made a DESIGN choice to KEEP using a system capable of feeding contaminated engine air into a sealed tube full of passengers, pilots, and flight attendants. Zero regard for their well-being in order to save a few pounds and eck-out more miles per gallon.
Flight crews spend thousands of hours breathing this air over their careers. Passengers have no meaningful ability to know when contamination occurs or opt out. Manufacturers and airlines alike are afraid to put contamination sensors on their planes because it exposes them to liability - it shows the true extent of the problem.
That is not an acceptable health standard in 2026, and it wasn't when these decisions were made. Fix the source, stop pretending filtration alone solves it, and make bleed-air-free cabin ventilation the standard for new aircraft. Demand this from your regulator or determine who is responsible for your health effects.
> This is so pervasive you'll see airline attendants spraying glycol-based air fresheners during these times to COVER UP the smell of this toxic stuff
I've never once seen a flight attendant do that. Flown hundreds and hundreds of times. You'd think something that's "so pervasive" would have been common enough that I'd have seen it dozens of times?
https://farahandfarah.com/blog/toxic-airplane-fumes-workers-...
Feels like youre defensive about this would love to know why. If you havent seen aerosols on a flight youre being disengenous or are not looking up/around. They are used for lavoratories and pest fumiagation during passengered flights regularly - and those are uses we agreed to as a society. Ive seen firsthand them sprayed during takeoff and landing at the time fume events are most noticed by passengers.
Disclaimer: I am an aviation enthusiast and loves planes and their design. I am unaffiliated with any airline or manufacturer. I want everyone to breathe ok.
2 replies →
> These incidents are literally called "fume events"
Your first FAA link says that these 'fume events' are rare: "The report found that the rate of cabin air quality events is less than 33 events per million aircraft departures." This is about one event every 30,000 flights.
I have a pretty sensitive sense of smell, and I regularly smell oil/smoke/hydrocarbon smell after they're starting the engines. It also sticks on your clothes after the plane ride, and I'm quite sure it's not just stinky seat smell.
6 replies →
https://www.cbsnews.com/sanfrancisco/news/study-shows-toxic-...
If you think of the last 10 flights you were on, how many had the gym sock smell? That's the real occurence rate. I'd say in my experience across all airlines its around 7/10 flights I can detect via smell a fume event.
11 replies →
That sounds awful; it means 3+ times a day a whole plane of a passengers is getting sprayed with this stuff.
There are more than 100,000 flights per day. So not that rare at all.
The article specifically says flight attendants are only at increased risk of radiation related cancers, but not others.
Quite interesting. My reaction is that one of these is much more easily controlled and an input for cancer than the other. Radiation shielding is a tougher solve due to weight and other factors, where air quality is an easy, known fix.
Would love both to be solved, which would lead to good outcomes. Any thoughts on why attendants have different outcomes?
6 replies →
The Boeing 787 has a bleedless system. It uses dedicated electric compressors for the cabin air.
That's interesting to know (thanks for calling it out!), and makes me feel extra glad I've worn a mask during the entire flight on every flight I've been on since 2020 (not that I've been on many)... turns out I was avoiding a lot more than just COVID etc. heh >_<
I believe the pilots air source works differently than the rest of the cabin - at least on the 737. Maybe that explains the difference between the pilots and the flight attendants.
The 787 in economy (as configured by most airlines) is hell in every other way so boy what a quandary
> oil, hydraulic fluid, or other contaminants
Will safe aerospace batteries spare us from this?
Recently designed a sustainable thermofluid that it says would work as hydraulic fluid and a de-icing fluid: LBGPC: Lignin, BioPG, Graphene, Phytic acid, Citric acid
Like others, I have zero experience with any of the things you are mentioning, but I want flying to be more expensive, more luxurious, and far more comfortable in general for everyone so please keep giving them a hard time about this.
In general, 50% or more of the people flying should not be flying, and going back to the pre-privatization era alongside much stricter regulations on seat sizes would be awesome as it would force actual economics of scale to kick in for the good seats and keep the burger king crown wearing crowd ( https://www.youtube.com/watch?v=onib3bDo6Z0 ) off these airplanes for good.
Feel free to pay extra for the fancy seats up front, known as either first class or business class depending on the airline you're flying (I've seen other names for them like "premier" or something, too). But if you keep up the "I know what's best for other people" attitude that you display in your second paragraph, don't be surprised if people start thinking... poorly of you. (I rewrote that sentence multiple times. That's the kindest way I can put it. A lot of my earlier drafts were... more unkind).
2 replies →
Oh how the middle class hates having to share with the poor.
We don’t mind the rich flying private jets, but for the love of god don’t put a poor person next to us on a plane.
1 reply →
The CNN article has more info on the study, for those without access to download it:
https://www.cnn.com/2026/08/19/health/flight-attendants-pilo...
Thanks! I've put that link at the top and moved the paper link to the toptext.
[dead]
[dead]
[stub for offtopicness]
(We've since changed the top link.)
paywalled (even with a "free" account")
It was a cross-sectional analysis of U.S. death certificates from 2020-2024, covering ~13 million deaths across 503 occupations, including roughly 14,000 pilots and 7,000 flight attendants. The analysis adjusted for age at death, sex, race/ethnicity, education, and marital status.
So in other words, breast cancer was the cause of death at a rate 61% higher for flight attendants than for the comparison population of other occupations.
2 replies →
It’s wild I can’t even read the abstract to understand what they found.
3 replies →
Yep. Your time is FREEEEE!
Paywalled garbage, even if you waste your time "signing up."