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meatlover
27th Aug 2018, 11:23
Good day gents,

I know this may seem like a silly topic to some, however my worry comes for a few reasons.
I started flying very young, and over the last 3 years, I have been doing long haul in a Middle East based Major carrier..
We not only fly at very high level (390-410 on a regular), but we also do US trips where we are cruising at higher latitudes of 70N. Though a latitude that high is uncommon, normally around the mid 50s, I tend to try and avoid US trips, and stick to Europe and Asia, or even Middle Eastern flights.
I expect to be doing long haul for another 2 years before I move over to the narrow body again for my command.

I can't help but be worried that this radiation will take a toll on me when I decide to start a family some day.
I'm looking to hear from other's experiences, and to see if anyone can shed any light on any measures that can be taken that will help at all.

Thank you in advance and best regards!

yxcvmnb
27th Aug 2018, 11:35
Well,

I can't comment much on the radiation accumulation and it's effect, haven't read that many studies.
But,

Why not start a family now, to play it safe :}

Side note: I've actually flown with captains who were uneasy about climbing to FL380, concerned with radiation.

meatlover
27th Aug 2018, 11:41
Well,

I can't comment much on the radiation accumulation and it's effect, haven't read that many studies.
But,

Why not start a family now, to play it safe :}

Side note: I've actually flown with captains who were uneasy about climbing to FL380, concerned with radiation.

Actually same here, have flown with colleagues that would prefer not to.
I presume climbing high but farther away from the poles should not be nearly as bad. I know guys that fly private charters etc fly even higher. We have all flown with guys that are significantly older and just starting a new family with their third wife :D
My issue is trying to stay away from the higher latitudes, and also looking to see if others can shed light through their own experiences.
The short haul does not sound too bad anymore. Lower levels, much farther away from higher latitudes, and similar time zones! Yep :D

Buswinker
27th Aug 2018, 13:05
(Not my field of expertise but putting it out there)

if reproduction is your only concern you could perhaps bank some sperm? (Or eggs, whatever takes your fancy)

i worry more about the cancer risk myself but then I’m an old fart!

KenV
27th Aug 2018, 13:13
I can't help but be worried that this radiation will take a toll on me when I decide to start a family some day.
I'm looking to hear from other's experiences, and to see if anyone can shed any light on any measures that can be taken that will help at all.
Thank you in advance and best regards!It may take a toll on you, and will certainly take a toll on your swimmers. But seeing as you produce a whole new batch of swimmers every few days, you needn't worry about reproduction a few days after you stop exposure to the radiation. If on the other hand you are a female, you are essentially born with every egg you will ever have and if they get irradiated, then your reproductive days are over.

Ian W
27th Aug 2018, 15:27
For those interested read this Report/Web page from the CDC - National Institute For Occupational Safety and Health NIOSH Website on Aircrew Exposure to Cosmic Radiation (https://www.cdc.gov/niosh/topics/aircrew/cosmicionizingradiation.html) and the FAA tool for calculation of each flight exposure (http://jag.cami.jccbi.gov/cariprofile.asp)
As you will see from reading the sites there is not a lot of certainty and a great degree of caution. As the Sun is now 'quiet' the solar wind is reduced and galactic radiation 'cosmic rays' entering the atmosphere are increasing. This will be the case until the Sun moves into the next Solar Cycle #25 and the solar wind increases reducing the number of cosmic rays from reaching Earth.

wiggy
27th Aug 2018, 21:36
As you say Ian it’s complex....a lot of the modelling, such as the various FAA tools such as “CARI”, look only at cosmic rays and as you rightly say as the Sun becomes more active around Solar Max the cosmic ray count reduces..so in the surface that sounds (and is good thing)

However problem then is that around Solar Max you are at increased risk at getting a real short term spike in radiation from a solar particle event....

Avoid high altitudes at high geo-magnetic latitudes (roughly the Poles, northern Canada) is probably the way to handle it if it is something one is fussed about.

Farm gate
28th Aug 2018, 01:56
A few studies by the Danes and the Kiwis, back at the turn of the century highlighted the significant increased risks of contracting Leukaemia, specifically Acute Myeloid Leukaemia (AML) for long haul pilots. I fly long haul, and I have a child recovering from AML. Do a search for the following:

Radiation-induced acute myeloid leukaemia and other cancers in commercial jet cockpit crew: a population-based cohort study.

giggitygiggity
28th Aug 2018, 04:09
Bored as I can't sleep so from a very non-scientific internet search I'd say it could be an issue. I calculated the mSv you'd accumulate flying from 65N to 65N via the North Pole (OULU, Finland to FAIRBANKS, Alaska - North Pole-ish as I got bored trying to think of airports that were suitably located), you'd get a dose of 0.0615 mSv per flight (conservatively estimating 7hrs for each sector). If you did 900hrs a year doing this same flight, you'd pick up 8 mSv of cosmic radiation. EASA 'recommends' that air crew don't exceed 6 mSv a year, so that's potentially more, but not excessively more than the recommendation. I'm not sure how the radiation calculator calculates the figure, but maybe in some cases it's worth investigating further. Perhaps you could buy a commercial dosimeter? Although I'd imagine a pair of lead plated boxer shorts would be cheaper!


From the CAA website (link below)
Individual monitoring is to be regarded as best practice but it is recognised that this can impose unjustifiable cost for some operators. In these circumstances an acceptable course of action would be to rely on an assessment of maximum doses where this shows that air crew will not be approaching annual doses of 6 mSv. A suitable cut off point would be where the assessment indicates a maximum annual dose of 4 mSv. Where air crew are liable to receive doses in excess of 4 mSv per annum, it is recommended that there should be monitoring of individual air crew member's exposure using computer program prediction. The purpose of such monitoring would be to ensure that annual doses did not exceed 6 mSv.

Where an assessment of maximum doses indicates that air crew are liable to exceed 6 mSv per annum, individual monitoring must be carried out. In addition, operators should adjust an air crew member's roster to reduce exposure with the aim of preventing, where possible, doses in excess of 6 mSv per annum. Records for individuals exposed to more than 6 mSv per annum must be kept for a minimum of 30 years from the last annual exposure of more than 6 mSv (even if the individual concerned is deceased) or until the individual is 75 years of age, whichever is the longer period of time.
https://www.caa.co.uk/Our-work/About-us/Aircrew-exposure-to-cosmic-radiation/


Feel free to check my maths at the sites listed below the screenshots.

https://cimg3.ibsrv.net/gimg/www.gmforum.com-vbulletin/1000x354/msv1_330d7a3b39417cb9a7e1a59b09fc429bb4829893.jpg

https://www.sievert-system.org/#Calcul
https://cimg0.ibsrv.net/gimg/www.gmforum.com-vbulletin/856x184/msv2_f694778e106bdb8d7283deaf588f6b39d036ecd1.jpg

https://cimg3.ibsrv.net/gimg/www.gmforum.com-vbulletin/629x800/msv3_582960dff02180ece8e6d8fd27d94acfe083bcf7.jpg
Great Circle Mapper (http://www.gcmap.com/mapui?P=OUL-FAI)

hunterboy
28th Aug 2018, 04:21
AFAIK, under EASA, airlines have to keep a record of a crew members exposure to radiation. Many do this via the CARI programme integrated into crew rosters. Is it worth asking your admin department? As far as measures to minimise go, I assume it is nearly impossible to reroute to lower latitudes in your airline, leaving flying at lower altitudes as the only method. Personally, I don’t go above FL350 if I can help it above 60N. If that means sticking on an extra tonne or two, so be it.

B2N2
28th Aug 2018, 07:09
I think the drive the airport is potentially more hazardous to your ability to produce offspring.


If you’re this concerned go crop dusting....really.






The chemicals will make your sterile.....bugger.






Become a simulator instructor and live like a mushroom in the dark.
Till a King Air has an engine failure and rolls into your building.


Maybe stay at home in bed.

wiggy
28th Aug 2018, 08:00
I'm not sure how the radiation calculator calculates the figure, but maybe in some cases it's worth investigating further. Perhaps you could buy a commercial dosimeter?

FWIW I used the CARI program many years back to track my exposure - since (as IanW mentioned) the level of Galactic cosmic radiation reaching the upper atmosphere depends upon the Sun''s level of activity (cf. Solar wind) CARI used to use an observed variable called the heliocentric potential (for which you had go online to the likes of NOAA) in it’s algorithms to in part calculate your exposure...that variable at the time was available for I think monthly Intervals. It is possible later versions of CARI will pick that value up automatically once it knows your flight date but I haven't looked at it for a while. Also CARI needs your route and very importantly your flight’s vertical profile. Fundamentally if you want to track your own exposure accurately, rather than come up with generic figures, you need to do a bespoke calculation for your flights, which involves quite a bit of book keeping for every sector regarding date, level changes and route taken and other stuff in order to produce anything really meaningful - simply entering AAA to BBB and a mean flight level can lead to considerable errors.

I did all this this for a year on longhaul and it worked out generally at very roughly 40 micro (uSv) on a Europe -Midwest USA sector and less on other routes.

As for easily avaliable commercial personal dosometers - my contacts tell me there''s nothing really easilly available to the individual as a single device that will cover the full "spectrum" of radiation we are exposed to with adequate sensitivity across the range of radiation types...but I know some disagree.

(Edit to add: For info found my records. Year was 2000, so around a Solar Maximum, aircraft 744 so assume start cruise low with FL’s low 300s end up high FL 300s

typical approximate doses calculated by CARI :

Typical highest “dose” sector Europe -Japan, 50ish uSv
Europe-West Coast States high 40 uSv
Europe-eastern Seaboard 30 uSv
Europe -Central Africa 20 uSv
Europe -South America 30 uSv

Jwscud
28th Aug 2018, 14:42
It’s a fraught subject. Some Captains are keen to stay low, certainly below 400+ for that reason. I used to routinely fly up to 470/490 on biz jets. 490 was the artificial ceiling imposed by the operator as at 490 or below the EASA record keeping for exposure is essentially a book keeping operation based on time flown whereas above 490 specific individual monitoring was required. I don’t know the exact details, but I can confirm that I have (currently - touch wood) healthy children despite both mid-latitude high altitude stuff and long haul northern canada/Russia.

Od course, the plural of anecdote ain’t data, you pays your money &c.

compressor stall
29th Aug 2018, 06:48
There was a thought that one side affect was that it would increase the likelihood of having offspring of the female gender.

I've thought about starting a survey of pilots to determine the veracity of that theory.

Intruder
29th Aug 2018, 21:02
Just make yourself a lead jockstrap.

hoss183
30th Aug 2018, 10:03
As a previous poster said, for males its not a big issue, as new swimmers are made regularly. Just leave a gap ( a week?) between flying and doing the business. For females its another story sadly.
The simulation with 61uSv seems about right, and its not nothing. I work with radioactive sources and my planned yearly dose is 50uSv. Although health problems should not occur until much higher doses. Its not so much a problem of how high you fly, but how many hours per year.

wiggy
30th Aug 2018, 13:45
Thanks for posting that..as much as anything because it prompted me to get my m’sand my u’s sorted out in my earlier post :\

I was typically picking up about 220 uSv a month , mixture of routes, when I did my logging, flying about 65-70 hours a month (those were the days).

If the high altitudes still bug people it is worth running dummy sectors with the same profiles, e.g. east/west high latitude vs. North south through the likes of CARI to see where the problems really lie and why “capping” levels down near the equator is almost pointless....

Chris Scott
30th Aug 2018, 21:05
I think the drive the airport is potentially more hazardous to your ability to produce offspring.
If you’re this concerned go crop dusting....really.
The chemicals will make your sterile.....bugger.
Become a simulator instructor and live like a mushroom in the dark.
Till a King Air has an engine failure and rolls into your building.
Maybe stay at home in bed.

I'm with B2N2 on this one. Is the OP a member of the Snowflake generation, by any chance? :rolleyes:

To be serious, am afraid I can't offer any technical knowledge on cosmic radiation, except that it presumably becomes more of a problem above the tropopause? So I take the point about polar flying - even at relatively low cruise levels. Anecdotally, I can say that I'm male and conceived several children (including one boy) in my twenties while on long-haul jets that frequently flew above the trop.

Onceapilot
1st Sep 2018, 16:38
IMO, there is a statistical increase of risk from harm by radiation at increasing dosage. However, the harm done may not show itself for decades, the percentage of current professional aviators who display symptoms is low-ish and there is never (in the case of long term background level increase) any specific evidence that any particular radiation dose caused a specific harm. Notwithstanding this, radiation damage does occur but, again IMO, regulating authorities and employers have long colluded in downplaying the damage risk.:oh:

OAP

megan
2nd Sep 2018, 05:46
Some papers on the subject.

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20070028831.pdf

https://oem.bmj.com/content/59/7/428

Extracts from the latter, In assessing risks, it is important to remember that extrapolations are only as good as their underlying assumptions. Little is known of the radiobiological effects of low dose ionising radiation, much less that of low dose ionising radiation of the type and quantity which airline pilots and cabin crew are exposed to at altitude. A great deal of what we assume is therefore inferred by extrapolating from experience with high doses.

Here, there are good grounds to think that the health risk of exposure to cosmic radiation is not zero. We know, for instance, that radiation mutagenesis principally proceeds through DNA deletions, and misrepair and misrecombination at DNA double stranded breaks. We also know that a single track of low energy ionising radiation can produce a double stranded break in the DNA of a single cell nucleus. A study of astronauts on a 4 month mission to the Mir space station (dosage received: 147.5 mSv) has shown significantly increased frequency of chromosomal aberrations after the flight, compared with samples obtained before the flight. A significant increase in chromosomal aberrations has also been found in Concorde pilots compared with controls, and indeed the same has been found in civilian pilots and cabin crew of subsonic aircraft.

Even more worrying is the discovery in 1992 of a previously unknown pathway termed “radiation induced genomic instability”, by which radiation can subvert living cells. It was previously thought that when ionising radiation hits a living cell and damages its DNA, only when the damage is not satisfactorily repaired is it passed on to the daughter cells; now, repeated experiments in vitro and in vivo have shown that radiation can additionally inflict damage that shows up only after several generations of cell division. This is particularly worrying as it raises the spectre of delayed genetic effects on the gene pool of future generations.

wiggy
2nd Sep 2018, 06:57
Here, there are good grounds to think that the health risk of exposure to cosmic radiation is not zero.

That’s not exactly breaking news....the problem is quantifying the risk.

The closest I have ever heard to an official figure was back in the late 90’s when an American sources stated an estimated that a twenty year career in Longhaul flying increased your risk of suffering of cancer or a cancer related illness by about 1%. (Haven’t got the reference easily to hand, sorry) It might be worth considering modern career patterns and the changes in fostering and modern flight profiles .

Now whilst you might find that order of magnitude frightning to get that into context these days in the developed world roughly 40% of us will suffer from cancer if some form in our lifetime and currently about 1 in three of us will die from the disease though treatments are improving.

I’ve always been inclined to think that given everything else we are exposed to in and around this job (sleep disruption, time zone changes, disrupted eating habits) plus day to day environmental factors, plus genetic factors radiation exposure in flight is something to think about, not worry about.

andytug
2nd Sep 2018, 08:57
For comparison, the average yearly background dose from merely living in Cornwall is around 7mSv, so probably best not to move there if you fly a lot ....
Due to underlying granite that emits radon iirc (see also Aberdeen).
It's very difficult to quantify this kind of risk, we know that walking near a live reactor core will kill you pdq, but not enough is known about the effect very small doses over a long period because it's hard to eliminate all the other factors that affect life expectancy (air pollution, diet, alcohol, smoking, etc etc.). Humans like to have yes /no answers, not probabilistic ones.

megan
3rd Sep 2018, 03:26
The closest I have ever heard to an official figure was back in the late 90’s when an American sources stated an estimated that a twenty year career in Longhaul flying increased your risk of suffering of cancer or a cancer related illness by about 1%.wiggy, covered in the NASA paper.Health Risks of Cosmic Radiation
1. Development of cancer.
A cell may become cancerous as a result of being irradiated, the likelihood being dependent upon the energy and the dose received. For an accumulated cosmic radiation dose of 5 mSv per year over a career span of 20 years (a typical prediction for a long haul crew member), the likelihood of developing cancer will be 0.4%. The overall risk of cancer death in the western population is 23%, so the cosmic radiation exposure increases the risk of cancer death from 23% to 23.4%. For a career span of 30 years, the cancer risk increases from 23% to 23.6%.
2. Genetic risk.
A child conceived after exposure of a parent to ionising radiation is at risk of inheriting radiation-induced genetic defects. These may take the form of anatomical or functional abnormalities apparent at birth or later in life. The risk following an accumulated dose of 5 mSv per year over a career span of 20 years will be 1 in 2,510. For a 30-year career, the risk increases to 1 in 1,700. Again this needs to be considered against a background incidence in the general western population of approximately 1 in 51 for genetic abnormalities, with 2 – 3% of liveborn children having one or more severe abnormalities at birth.
3. Risk to the health of the foetus.
The risks to the foetus from ionising radiation are cancer and mental retardation. There is a background rate of around 1 in 39,000 for neonatal lymphoblastic leukaemia and 1 in 170 for childhood mental retardation within the general population. It is estimated that exposure of the foetus to cosmic radiation for 80 block hours per month will increase the risk by between 1 in 6,000 and 1 in 30,000 depending on the routes flown. The increased lifetime risk of fatal cancer from 1 mSv received during prenatal development is 1 in 10,000 (0.01%).
4. Non-cancer Effects (Degenerative Tissue Risks)
The most important of the non-cancer risks due to radiation exposure are degenerative diseases including heart and digestive diseases, early and late effects in the central nervous system, and cataracts. Non-cancer effects are thought to be deterministic in nature, occurring only above a dose threshold well above aviation doses and most space missions, except for a Mars mission or extraterrestrial exposure to a large SPE. However, recent epidemiological studies indicate threshold concepts do not seem to hold indicating these risks are a concern for spaceflight.

wiggy
3rd Sep 2018, 08:07
Thanks for tracking that down megan., .

I realise my closing comment in my last post about might well appear a bit flippant...it wasn’t meant to be.

What I meant to say is is that IMHO exposure to cosmic radiation shouldn’t be at the top of anybody’s worry list about things we do and can control in this line of work (on and off duty) that can change our risk of developing cancer....

(A while long back, obviously, but as an example I remember working with a number of captains who would refuse an option of higher level because of their concerns about radiation.....and then having finished the brief discussion would in all probability light up another cigarette.....:* )

B2N2
3rd Sep 2018, 10:43
You may want to start by turning off the weather radar.
All that weather out there is bouncing back all this radiation.

Ian W
3rd Sep 2018, 20:20
There is a theory of Hormesis that says that small doses of radiation may actually be benign or even beneficial.

Hormesis is the stimulation of any system by low doses of any agent (Luckey, 1980a (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2477686/#B39)). Large and small doses of most agents elicit opposite responses. A dose that elicits a response which separates positive from negative effects is the threshold dose; it is the “zero equivalent point” (ZEP) for that specific parameter. Low dose is any dose below ZEP. Dose rate is also important. Taking one pill per day may be life-saving; taking 365 of most pills in one day would be lethal.

For those with an interest or time to kill: Radiation Hormesis: The Good, the Bad and the Ugly. Full paper here (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2477686/)

It's not all bad news - so relax in Cornwall or Aberdeen :D

misd-agin
4th Sep 2018, 12:47
If inflight radiation doesn’t kill them worrying about some other relatively minor issue will kill them instead.

B2N2
4th Sep 2018, 21:09
All giggles aside this is a very interesting website

SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids (http://spaceweather.com/)

underfire
4th Sep 2018, 22:21
I have a rad badge that measures radiation, it is attached to my id. This is from the days when I was flying into hotzones with EPA/DHS. Once it reaches a certain color, you cannot fly until cleared. Still have them on the id, just to keep a watch. You can buy them on the internet.
Home (http://www.jplabs.com/)

Go with rad triage, as the measured dosage limit begins very low. While it is for acute dosage, the timeframe of exposure they consider acute is a bit vague. Anyways, this is what we used.

Thi measures gamma radiation, which I guess is the harmful one (photons), but in what we call cosmic rays, there are photons (gamma rays), electrons, protons, nuclei, neutrinos, but the bulk of the "cosmic radiation" is protons.

Guess it is like butter vs margarine...

https://cimg0.ibsrv.net/gimg/www.gmforum.com-vbulletin/400x300/rad_triage_2_238a0f7227aa569536f9bf6a3c25999b005fff8f.jpg

Less Hair
5th Sep 2018, 08:50
I seem to vaguely remember some flight crew health study from the soviet union back then from a LONG time ago. One of the few where some truly huge commercial pilot population had been monitored. IIRC one of the surprises to me was that flight crew seemed to have some increased risk of heart problems due to high altitude radiation. Unfortunately it was a long time ago and I can't provide any link or details. Maybe someone else has it?

oggers
5th Sep 2018, 11:30
Why not post this in the medical forum

BARKINGMAD
7th Sep 2018, 21:10
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BARKINGMAD
7th Sep 2018, 21:24
Those lucky enough to have flown the AEW Shackleton 'twixt the 1970s to the 1990s didn't seem to suffer any damage to "swimmers", judging from the 8Sqn birth rate.

The 1940s designed radar under this 'frame allegedly transmitted enough wiggly amps into the ether that we weren't supposed to switch it on overland as it was rumoured to seriously affect the analogue TVs of that period.

The thermionic valve-powered AN-APS20 radar had a monstrous aerial requiring 2 special engine-driven generators to keep it powered, so although we're talking different radiation frequencies l question whether the cosmic variety actually competes with the "Shack" output coupled with the proximity of the crew to the source.

I never launched my "swimmers" on operational sortie(s) from choice but at least I'm still around to joke about it, for now. ��

PPRuNeUser0139
8th Sep 2018, 07:46
In addition to Barking's comments, <going off topic slightly> there was a school of thought on the squadron that linked what appeared to be a 'higher than normal' onset of cancers various with prolonged exposure to the AN-APS20.
I'm still chuckling over the lead-lined jock strap idea.. "Is that a lead-lined jock strap or are you just pleased to see me?"

andytug
8th Sep 2018, 08:06
From what I remember radar wavelength is closer to that of microwave radiation? So you wouldn't be irradiation your little swimmers so much as cooking them...