Exposure to Harmful X-Rays

[bealine]

As yet another former colleague has sadly passed away with cancer of the colon, we are becoming concerned at the number of deaths among our airport colleagues from digestive tract tumours.

Every day, our personal items are subjected to x-ray screening through "Rapiscan" scanners, including any food we take through. If we purchase food or beverages at work, that has all been x-rayed too.

Obviously, the radiation from x-rays gradually disappears but we have suspicions that we may have a cumulative effect by continually ingesting irradiated food and handling mobile phones, mp3 players etc that have been x-rayed thousands of times.

Now, I notice that my British Airways' dentist is very careful to leave the room before x-raying my teeth and when he referred me to Guys hospital, they were very careful to step out of the room too!

Can anyone who knows about radiation provide a deinitive answer, please, as to just how much dangerous x-ray exposure we are facing? Thanks!

[hunterboy]

The BA Intranet shows BA crew their accumulated dose using the CARI6 program. Its under Travel.....

[bealine]

Yes - but crewing and Cosmic Radiation is not the issue!

I am asking about the effects of "Rapiscan" administered x-rays to my personal property and food - I mean even using my steel ballpoint pen, or using my mobile phone for many hours after scanning will mean I am absorbing x-rays through my skin!

How much more x-ray radiation can I take before I fall victim to the Big C?

[mphysflier]

OK - as a radiation oncology physicist I'll have a go at clearing up a few things....

Firstly, as far as irradiation of food etc goes, there is absolutely no 'residual radiation' or radioactivity emanating from anything which has been exposed to low-energy (KiloVoltage) x-rays such as used in security scanning equipment. Its only when you get up to really high energy stuff (10 MegaVolts and above) as sometimes used in radiation therapy that any 'aftereffects' are seen in the form of neutron activation, and thats way out of the league of any airport scanner. Anything you touch or use after it has passed through is not having any effect on you whatsoever.

At the atomic level, the item passed through the scanner may suffer some ionisation and subsequent production of free radicals which, from a single scan, would have no significant effect on it. If it were sensitive electronic equipment then theoretically it could be damaged by undergoing a huge number of scans, but in the case of food there's not going to be anything different about it. Industrial irradiation of food to much higher levels in order to destroy microorganisms has been common practice for a while and the effects of this carefully studied - again, the doses involved are orders of magnitude larger than the scanner doses we're talking about here. This aspect of your occupation is much less likely to be a hazard than the 'western' dietary aspects which are an acknowledged risk factor for all of us eating too much fat and not enough fibre.

Secondly, your dentist is only doing exactly as he should as an occupationally exposed worker. You may only have maybe 20 medical x-rays in your life to accumulate radiation exposure - he may end up x-raying thousands of patients over his career so even though he wouldn't be directly in the beam he'd cop a bit each time and it would add up. There are well defined rules and dose limits for all radiation workers to minimise the risks involved, and there are also limits on how much members of the public may be exposed too, although these limits exclude justified medical exposures such as your dental x-ray.


Now, as for exposure of flight and cabin crews to cosmic ray irradiation...that's been covered elsewhere I think!

[gingernut]

bealine, I can't see the link, as the phone and pen don't retain the irradiation once the scan has been performed.

The danger would arise if you were exposed during the scan itself, not from the scanned material.

The dentist leaves the room and covers his gonads with lead whilst the x-ray is being performed, but is quite happy to operate on the patient unprotected.

Have you got any epidemiological data linking bowel cancer and piloting? (I've not seen any),

cheers ginge:)

[bealine]

bealine, I can't see the link, as the phone and pen don't retain the irradiation once the scan has been performed.

au contraire! Everything scanned will retain a certain amount of radiation for a while afterwards. Howe much radiation is absorbed and how long for depends on the amount of radiation received and the material in question.

My Chemistry lessons at school are, unfortunately, a distant memory but there was a formula for working out radiation absorption and the speed at which the radiation disappears. I bet my ballpoint pen would still contain radiation from yesterday's scan when i turn up for work today!

Maybe I'll buy a Geiger counter and then I can publish my results!

By the way, we're not talking about pilots here who only get their stuff x-rayed every day or two, we're talking airport workers whose bags can be scanned up to four times daily! ......and amongst Heathrow Airport workers, there is a disturbing anecdotal trend of digestive tract cancers - indicating something amiss with ingestion of food (although harmful asbestos has also recently been removed from ceilings which could be a cause.)

[gingernut]

well ya live'n'learn.

Try a search, there was much discussion about 6m ago:)

[mphysflier]

No - what you say is incorrect. At the low (KiloVoltage) energies used by these scanners there is absolutely no 'residual radiation' present in anything. At really high energies (completely out of this league) you can create neutrons, but NO WAY here. Your pen, food etc is no different afterwards.

Your dentist is only following occupational rules - you may only have perhaps 20 x-ray examinations in your life to tot up your lifetime exposure - he may be involved in 1000s in his career and cop a little bit each time, so there are rules in place to limit his exposure.

The likely major risk factor for bowel cancer that you and your colleagues are exposed to is nothing to do with low energy, low dose airport scanners - it's a high fat, low fibre western diet.

And as for flight crew and cabin crew exposure to cosmic rays, i think that has been discussed before at length.

[rexmundi]

If you eat lettuce from a sandwich that has gone through a x-ray scanner it must have it's DNA altered by scanners. Eating this an hour or two after scanning when the cells of the lettuce are still dividing and replicating must lead to some strange effects within the lettuce (mutant vitamins, proteins) This may be cancerous but dont think anybody has really researched this.

[mphysflier]

Try this link, and the others it refers to:

http://www.physics.isu.edu/radinf/food.htm

Bear in mind this is talking about radiation doses orders of magnitude larger than anything an airport scanner can deliver.

[znww5]

Guys - there is no residual radiation left behind after an x-ray exposure at all. Even the x-ray generator itself does not retain residual radiation, when it is switched off it is perfectly safe to handle.

The risk is from direct, personal exposure to x-rays, which in the case of cabin crew comes from flying at high altitudes where the thinner atmosphere provides less protection from x-rays and other radiations emanating from the sun. The aluminium skin of the aircraft provides a limited amount of protection, but does not screen all solar radiation.

Radiographers will often tell their patient that a chest x-ray will give them an x-ray dose equivalent to that received during a flight across the Atlantic. So, conversely a daytime crossing (no solar radiation at night of course!) will give all aboard a dose equivalent to a chest x-ray.

The health risk therefore is derived a) from the greater number of flights taken by cabin crew compared with pax and b) the fact that solar radiation is not constant - occasionally it can be 10 times stronger - even 100 times stronger on very rare occasions. Naturally, if the solar radiation increases, the received dose increases as well.

So, the risk is not from what happens on the ground - it is from what happens 'up there'.

Hope this helps :)

[obgraham]

If you eat lettuce from a sandwich that has gone through a x-ray scanner it must have it's DNA altered by scanners. Eating this an hour or two after scanning when the cells of the lettuce are still dividing and replicating must lead to some strange effects within the lettuce (mutant vitamins, proteins) This may be cancerous but dont think anybody has really researched this.Now why in the world, on a part of the forums usually kept factual, would you put out such twaddle? There is not the slightest bit of truth to your post.
Cancer does not come from eating radiated food.

[Pontius Navigator]

My Chemistry lessons at school are, unfortunately, a distant memory

Maybe I'll buy a Geiger counter and then I can publish my results!



Bea, save your money. By your definition, a geiger counter that proves your theory is correct will not work.

You have a radiation source.

You have a geiger counter.

You use the geiger counter to locate the radiation source.

The geiger counter is irradiated and retains this radiation.

The geiger counter is NOW useless as it will always react to ITSELF.

~~~~~~~~~~~~~~~

Obviously b:mad:s as I would not have been able to locate the numerous RA sources around the field during exercises.

[bealine]

Okay - I will bow to your superior knowledge on the subject concerning the small amounts of x-rays used to scan my personal items every day!

I was interested to read the comment concerning electronic items though! My wife and I both go through mobile phones like a dose of salts! Mine is just starting to act very strangely and it's only six months old, Mrs Bealine has never had a phone longer than 9 months without problems developing.

I've gone through three mp3 players in a year too (Sony must be laughing!)

The funny thing is, our children can hang on to their mobile phones for two years or more, only changing them because they are no longer trendy!

Does this mean Mrs Bealine and I can claim new mobile phones and mp3 players from the BAA or DFT? :hmm:

[bealine]

The geiger counter is NOW useless as it will always react to ITSELF

Of course! When I used to use these a Geiger counter in the army, we were forever having to change the probes for this very reason!

[aussiepax]

look, you air guys have just had the expert opinion of a rad onc physicist, and you are still arguing the point. I thought scientific and logical thought would have been valued in aviation ... why are you you bringing up pseudoscientific crap in posts since? This really baffles me and makes me doubt the sincerity and sanity of those posting such rubbish. Please let me know if you get a job here in Oz so I can avoid those flights. It's like telling me that you can navigate by the signs of the zodiac and the pilot's aura !

[mphysflier]

Well, I guess we are all here to educate ourselves and others where we can. I'm happy to help fight radiation paranoia just as others on here have helped me understand things like what an APU is and why a Qantas 767 can fly with an inop one!!

:)

[wiggy]

No no no, it's not the Sun!! The "fact" that the Sun is the main source of radiation at the higher Flight Levels is one of the biggest urban myths in the aviation world. ...the main culprit is Cosmic (i.e. deep space) radiation that has it's origin way outside the Solar System - daytime/nighttime doesn't matter and paradoxically when the Sun is at it's most active it's magnetic field actually shields the Earth from Cosmic Rays..., reducing the level of incoming Cosmic Radiation. That said you will get very occasional spikes in the level of Solar radiation, usually associated with Very active Sunspots and or Coronal Mass Events.


Funny how crew get wound up about nasty cosmic radiation and then bake themselves in the sun at Elevations of 5000' plus without "slip, slap, slopping".


mphysflier

Thanks for your input, good stuff.

[Pontius Navigator]

Of course! When I used to use these a Geiger counter in the army, we were forever having to change the probes for this very reason!


No Bealine, you were changing the probe head cover because it had come in contact with and was now carrying the contaminant.

In your argument the contamination of the geiger counter would not stop at the probe but continue through the device to the sensor. Nice try.

PS, a dosimeter does become 'contaminated' as it measures the accumulative buildup of radiation at much higher levels. At security a dosimeter would also measure accumulations of radiation but would be insignificant compared with military radiation effects.

[bealine]

Indeed, it was the probe head cover we changed - sorry, it was rather a long time ago!

So, we are agreed then that x-rayed foodstuffs and personal items don't hold a cumulative dose of radiation?

Please don't shoot me - I am not trying to nit-pick, I just want to understand. In medical circles, if the internet is to be believed, concern is growing over the over-use of medical and dental x-rays, exposure to police radar and now the new x-ray body scanners being rolled out at airports. Apparently there is evidence of cell mutations and abnormal cell growth from a cumulative build up of x-ray radiation.

If, then, a cumulative build-up in human cells can occur, does not the same thing happen to meat and vegetable matter passing through an airport x-ray scanner - especially as the operatives often stop the bag inside the machine and bombard it with more x-rays to get a closer look at the contents?

I accept that maybe the "Rapidscan" x-rays are at a much lower strength than medical / dental x-ray scanners, but surely over a period of time of (we're talking 10 years plus) my colleagues and I ingesting, what is essentially, contaminated food then we can expect tumours to develop in the digestive system.

Certainly, the incidences of digestive tract tumours in recent years among airport ground staff would lead one to believe that something is amiss - if not x-ray exposure, then what else?

Sorry, whilst we have the opinions and knowledge of experts in the field here, which I respect, I am only asking because, whilst the answers so far seem convincing, there are areas which appear to conflict with medical opinion read elsewhere on the net.

[obgraham]

Bea:

You're mixing two issues.

It makes sense to keep your cumulative total body radiation exposure as low as practical. The absolutely 100% safe level of exposure is not known. However, the benefit from routine diagnostic and screening exposure is far below any known levels of danger. By several orders of magnitude. Meanwhile development of lower exposure equipment will and should continue. That's not the same as saying there is danger from current equipment.

As far as radiated food, you could Xray your baloney sandwich any number of times. It won't carry residual radiation to you. Food irradiation should be used more widely -- the rate of food poisoning would markedly decrease. Only public misconception has prevented this from being implemented. Like GM food (oh no, that's another one!)

[bealine]

Thanks, obgraham, I feel a bit happier!

.......Just a bit worried that there might be another reason for higher digestive tract cancers in airport staff that we haven't yet identified.

[Pontius Navigator]

Do you smoke?

What do you eat all the time?

On what did you base your initial suspicions that it was your work environment that causes the problem?

You never know, you might be right all along except that radiation from the machines or irradiated food is not the problem.

[gingernut]

.......Just a bit worried that there might be another reason for higher digestive tract cancers in airport staff that we haven't yet identified.


any specific evidence Bea?

It sounds like you've got genuine concerns, I 'aint an epidemiologist, but I guess your starting point would be to look at the incidence (new cases per year) and prevalence (overall cases at one time), and compare them to the population as a whole.

I guess then, you'd have a starting point.

You'd then have to look at the risk factors, (smoking, diet, alcohol, obesity etc), and compare them to the population as a whole, and somehow factor these into the equation. Is there a significant difference in expected rates of GI cancer then?

It's a bit complicated:)which is the reason I 'aint an epidemiologist.

[ooizcalling]

Had a colleague doing a walkaround inspection, then on returning to the cockpit found that the Radar had somehow been switched 'ON', or left 'ON' instead of being in 'Standby'. Now he's aware of all the warnings like eyesight and testies possibly being affected but what's the latest status considering that modern Radar's operate on a much lower power setting than the old Radars, frequencies are a little different, and that during a walk around you would only be in the 'beam' for a relatively short period of time even though very close to the Radome.

Can anyone give some advice on this short radiation exposure

What would / could happen in worst case scenario, any symptoms one should be looking out for, etc etc.

What are the risks nowadays ?

[IRRenewal]

http://hps.org/publicinformation/ate/q315.html

[ooizcalling]

Thank you 'IRR'.
Spot on !

[rexmundi]

It's not twaddle....

Cat-food irradiation banned as pet theory proved (http://www.smh.com.au/national/catfood-irradiation-banned-as-pet-theory-proved-20090529-bq8h.html)