Mir
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Radiation - How Do Airlines Avoid Overdosages?

Fri Apr 22, 2005 1:31 pm

I was kind of curious about what policies airlines had with regards to preventing radiation overexposure for flight crews. Obviously, you can't stop it entirely, but are there any special things that are done to minimize the damage?

Thanks,

-Mir
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Yikes!
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RE: Radiation - How Do Airlines Avoid Overdosages?

Sat Apr 23, 2005 6:54 pm

They avoid knowledge of overexposure by not measuring it in the first place. I've only seen one radiation measuring device onboard a civil airliner, and that was in Concorde.

Sound like an ostrich with its head in the sand?!
 
CosmicCruiser
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RE: Radiation - How Do Airlines Avoid Overdosages?

Sat Apr 23, 2005 10:36 pm

Most cargo crews wear radiation badges but it's not for solar radiation but for all the stuff 10 ft. behind the cockpit.
 
satx
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RE: Radiation - How Do Airlines Avoid Overdosages?

Sun Apr 24, 2005 4:04 am

Quoting CosmicCruiser (Reply 2):
Most cargo crews wear radiation badges but it's not for solar radiation but for all the stuff 10 ft. behind the cockpit.

Apparently, only on the long-haul flights with regard to FedEx. It's funny how the rest of the workers along the way are left to fend for themselves. Then again, you have to wonder what the pilots would do if they noticed they were getting too much exposure half way across the atlantic. They wouldn't have too many options.

"Nearly all the radiation doses received were estimated doses, since the FedEx employees involved in transporting the package did not wear dosimeters, apart from the pilot and co-pilot of the transatlantic flight."
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CosmicCruiser
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RE: Radiation - How Do Airlines Avoid Overdosages?

Sun Apr 24, 2005 7:43 am

Quoting SATX (Reply 3):
Apparently, only on the long-haul flights with regard to FedEx. It's funny how the rest of the workers along the way are left to fend for themselves. Then again, you have to wonder what the pilots would do if they noticed they were getting too much exposure half way across the atlantic. They wouldn't have too many options.

I don't know where you got that info BUT every FEDEX pilot wears a radiation badge and it is required. A new badge is issued every month and the old one is sent to a lab for developing. You have no warning in the event of exposure so you won't know. The history shows no over exposure of any crews. One can (and I have) go to a co. website that will give you your previous readings and they avg. less than a dental x-ray. When I said most cargo crews I meant that MOST cos. would require it not just FEDEX.
 
sovietjet
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RE: Radiation - How Do Airlines Avoid Overdosages?

Sun Apr 24, 2005 9:15 am

Sorry for my ignorance but where would this radiation come from?
 
curlyheadboy
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RE: Radiation - How Do Airlines Avoid Overdosages?

Sun Apr 24, 2005 9:40 am

Quoting Sovietjet (Reply 5):
Sorry for my ignorance but where would this radiation come from?

From the sun. The higher you go, the thinner the atmosphere gets. Less radiation is filtered and some dangerous wavelengths can make their way through the aircraft hull. That's a problem the airline industry should put more efforts to solve... The pilots are of course the most exposed and could suffer damages to their health.
If God had wanted men to fly he would have given them more money...
 
CosmicCruiser
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RE: Radiation - How Do Airlines Avoid Overdosages?

Sun Apr 24, 2005 9:41 am

Quoting Sovietjet (Reply 5):
Sorry for my ignorance but where would this radiation come from?

Hazmat that is radioactive.
 
satx
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RE: Radiation - How Do Airlines Avoid Overdosages?

Sun Apr 24, 2005 9:44 am

Quoting CosmicCruiser (Reply 4):
I don't know where you got that info

It's a weblink. Click it. Then you'll see where I got the information.

Quoting Sovietjet (Reply 5):
Sorry for my ignorance but where would this radiation come from?

There are two main source categories discussed in this thread. The first is naturally occurring radiation, such as cosmic background radiation or even coronal mass ejections and the second is radiation from freight cargo. If you do a search with these terms on your favorite search engine, you will find plenty of details.

For instance...

The longer a person travels on a jet, the higher the jet travels and the closer the jet flies to the north or south poles, increase exposure to cosmic radiation, which comes from deep space and the sun. The Earth's atmosphere largely shields us from cosmic radiation, but planes fly where the atmosphere is thin.
Open Season on Consumer Protections is Just Around the Corner...
 
Glom
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RE: Radiation - How Do Airlines Avoid Overdosages?

Sun Apr 24, 2005 9:49 am

Cosmic radiation. The atmosphere is the principle shield against it, but at FL350, there is less atmosphere. I know a lot is made of the magnetic field. It contributes a significant amount of protection, but atmosphere contributes more.

For every hours of jetliner flight, you get around 10µSv of dose equivalent. Given that the legal limit for the general population is 5mSv per year and that around 3mSv is from other sources, mostly natural, that means that a person can fly around 200 hours a year and be within the legal limit.

Of course, for radiation workers, the legal limit is 25mSv per year. Since an airline pilot works in a high radiation environment, we can class him as such, therefore, he can fly 1000 hours a year and be within the legal limit.

Of course, the legal limits are very conservative and are based on the linear no threshold hypothesis, which is an assumption with no backing evidence and mounting contrary evidence.

Lets consider a more meaningful value, the threshold for the onset of cataracts. That's 15Sv life total. Let assume 60 good years before we don't are anymore. In that time, the background dosage will be 180mSv. That leaves 14.82Sv to be alloted to jet flying. At a rate of 10µSv per hour, the total number of jet hours can't be more than 1.5 million hours. That means that if we assume a 40 year career, that means that he shouldn't fly more than 37,000 hours a year.

I think our beloved flight crews are not in too much danger.
 
CosmicCruiser
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RE: Radiation - How Do Airlines Avoid Overdosages?

Sun Apr 24, 2005 9:55 am

Quoting SATX (Reply 8):
It's a weblink. Click it. Then you'll see where I got the information.

I'm sorry then because I've had to wear a badge since day one and so has every other FEDEX pilot. No one is left to fend for themselves. Your website has an error. Any flight no matter how short or long can carry radioactive hazmat. Above a certain level of TIs and additional readings are made. Above the min level and jumpseaters will wear dosimeters also and it's called a "hot flight".
 
Glom
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RE: Radiation - How Do Airlines Avoid Overdosages?

Sun Apr 24, 2005 10:15 am

Wow! Just checked my facts again. I made an error in my figures. The dosage due to jet travel is 5µSv per hour, not 10. So that means that the general public can fly 400 hours a year legally, aircrew can fly 2000 hours a year legally and long term health is only endangered if he flies over 70,000 hours in a year. There are, of course, less than 9,000 hours in a year.
 
satx
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RE: Radiation - How Do Airlines Avoid Overdosages?

Sun Apr 24, 2005 5:45 pm

Quoting CosmicCruiser (Reply 10):
No one is left to fend for themselves. Your website has an error.

1. So exposure to the warehouse workers and truck drivers is also measured? I haven't heard you comment on that yet. Regardless of who wears dosimeters, don't these devices merely tell your employer that you've been exposed after the fact? FedEx may be a great company to work for, but even without searching, I have come across about a half-dozen cases of unplanned radiation exposure related to FedEx shipments in the news. None of these cases were known to have harmed any pilots, but it's certainly probable that at least some employees were exposed unknowingly.

2. It's not 'my website,' it's just 'a website.' I have nothing to do with what they publish. If they made a mistake, then feel free to write them about it.

Quoting Glom (Reply 9):
Of course, the legal limits are very conservative

I think what you mean is that they are intended to be conservative. However, the mere fact that regulatory agencies around the world have found it necessary to lower them would seem to contradict that opinion somewhat.

Quoting Glom (Reply 11):
So that means that the general public can fly 400 hours a year legally,

Beyond workplace exposure, I'm not sure what legal aspect you are referring to. Can't the general public fly 1,000 hours if they can afford it? Just as they could presumably get 100 dental x-rays if they were willing to pay for them.

Warning, the rest of this post has a political component. If anyone wants to avoid a political discussion, you can simply skip over to the next post or to another thread.

--------------

As for workplace exposure, thanks to the recent handcuffing of the EPA, OSHA and other agencies, there is little for companies to fear from workplace exposure levels. As with nearly all his appointments, George Bush has chosen biased folks familiar with the motivation of only one side for a post that oversees two or more sides. It's called a conflict-of-interest, although you'll sometimes hear American conservatives call it an "opportunity."

Under John Henshaw, of Monsanto fame, roughly three-dozen proposed regulations for work-place safety were abandoned as being unfriendly to business. Only three potential regulations of significant economic impact remained on the table after Henshaw's work, one of which was there merely as a result of a court order. The new appointee, Jonathan Snare, has a background that includes representing corporations in labor law disputes. Sure, I doubt he's the slightest bit biased. No need to wonder if he represents the true interests of the average worker.

http://www.npr.org/templates/story/story.php?storyId=4256593


*In case you don't know about the wonderful work of Monsanto, among other things, they have sued a small dairy in New England for not using hormones in their milk and having the gall to print that fact on the label. From what I can tell, Monsanto's case is premised on the idea that consumers are too ignorant to make decisions on their own and thus cannot be trusted to understand such a label. Monsanto has also used their biotech division to ensure farmers can no longer collect seed from the one year's crops to use the following year and to allow agribusiness to increase their use of pesticide and herbicide by around 25%. Not a very good track record IMO.

http://www.npr.org/templates/story/story.php?storyId=4465105
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Glom
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RE: Radiation - How Do Airlines Avoid Overdosages?

Sun Apr 24, 2005 8:32 pm

Lowering a limit doesn't imply that the previous limit was dangerously high, merely that they are being more cautious/paranoid/desperate for something to do.
 
CosmicCruiser
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RE: Radiation - How Do Airlines Avoid Overdosages?

Sun Apr 24, 2005 11:32 pm

Quoting SATX (Reply 12):
1. So exposure to the warehouse workers and truck drivers is also measured? I haven't heard you comment on that yet. Regardless of who wears dosimeters, don't these devices merely tell your employer that you've been exposed after the fact? FedEx may be a great company to work for, but even without searching, I have come across about a half-dozen cases of unplanned radiation exposure related to FedEx shipments in the news. None of these cases were known to have harmed any pilots, but it's certainly probable that at least some employees were exposed unknowingly.

The original post asked how airlines protect FLIGHT CREWS from radiation and that's what I responded to. If you wish to delve into every aspect of radioactive handling from pickup to delivery I can investigate all of their procedures for you aside from this website. I know that HAZMAT handling is a serious and specialized field at FEDEX. That certainly doesn't mean there haven't been incidents that have involved injuries but they are few and often because a customer failed to declare the item HAZMAT or improperly packed it. BTW, considering what we carry on a daily basis, the low level radiation mat. is really the least of my worries.
 
satx
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RE: Radiation - How Do Airlines Avoid Overdosages?

Mon Apr 25, 2005 6:47 am

Quoting CosmicCruiser (Reply 14):
That certainly doesn't mean there haven't been incidents that have involved injuries but they are few and often because a customer failed to declare the item HAZMAT or improperly packed it.

From what I have read so far, you are right on the money. It's just unfortunate that in general the contamination wasn't discovered until after the delivery was made.

Quoting CosmicCruiser (Reply 14):
BTW, considering what we carry on a daily basis, the low level radiation mat. is really the least of my worries.

Fair enough. Thanks for the reply.  Smile

Quoting Glom (Reply 13):
Lowering a limit doesn't imply that the previous limit was dangerously high, merely that they are being more cautious/paranoid/desperate for something to do.

I never said "dangerously high." I simply implied that perhaps the previous limits were not best described as "very conservative." That's all. I know there is a general consensus among laymen that regulatory agencies are overbearing and overreaching in their restrictions, but in reality that is the exception and not the rule.

In most cases, widely recognized regulations are the result of serious harm or death to more than one person. Just because the need for a regulation is not blatantly obvious doesn't mean the regulation is unwarranted. Time and again folks have ignored standard safety regulations to their detriment. Having worked in dangerous fields before, I know that most restrictions were the result irreparable harm to many who had gone before us.
Open Season on Consumer Protections is Just Around the Corner...
 
Glom
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RE: Radiation - How Do Airlines Avoid Overdosages?

Mon Apr 25, 2005 7:37 am

Past experience has to do with a lot of regulations, but radiation is a difficult issue because their is much uncertainty about the reaction to low level radiation, hence the need to use the LNT. But clearly the intention is to be conservative so even a person is safe even in a margin above the legal limit.

As you see, 2000 hours a year can still be flown by aircrew while remaining within regulatory limits. I'm not sure how much the average airman does in a year but that is basically equivalent to working 8 hours a day 5 days a week within two weeks holiday.

Using the most definable detrimental health effect, this exposure is not even close to significant. Basically, it seems like radiation is not a high priority cause for concern when hurtling through the sky in a pressurised metal tube carrying a few tonnes of potentially explosive material.

Of course, perhaps the 787 might reduce exposure even further. Plastics are good at absorbing charged particle radiation.
 
bsergonomics
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RE: Radiation - How Do Airlines Avoid Overdosages?

Mon Apr 25, 2005 5:43 pm

I'm afraid that I read the report over 10 years ago, so I can't remember the reference. However, there was a long-term study that showed that long haul pilots were 40% more likely to get skin cancer than a ground-based worker.

I'll see what I can do to find the reference, but I can't promise anything.
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Glom
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RE: Radiation - How Do Airlines Avoid Overdosages?

Mon Apr 25, 2005 9:08 pm

Okay, I now have the theory that for every 1mSv-person, there are 13 cancers per million people.

So let's assume 2000 hours per year for 40 years. That's 80,000 hours. At 5µSv per hour, this adds up to 400mSv. That means that the risk is 5.2 in a thousand from jet travel. Of course, with 60 normal years at 3mSv per year, the baseline is 180mSv, which is a risk of 2.3 in a thousand. So the risk is trebled. Maybe that's not so good.

Of course, it should be stressed that this is based on the LNT, whose validity is in doubt.
 
cancidas
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RE: Radiation - How Do Airlines Avoid Overdosages?

Tue Apr 26, 2005 12:21 am

Most cargo crews wear radiation badges but it's not for solar radiation but for all the stuff 10 ft. behind the cockpit.

a friend of mine who works for EL AL cargo as a loadmaster has told time and time again that any radioactive materials are always packed at the very rear of an airplane to keep them as far away from the crew as possible.
"...cannot the kingdom of salvation take me home."
 
CosmicCruiser
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RE: Radiation - How Do Airlines Avoid Overdosages?

Tue Apr 26, 2005 12:46 am

Quoting Cancidas (Reply 19):
friend of mine who works for EL AL cargo as a loadmaster has told time and time again that any radioactive materials are always packed at the very rear of an airplane to keep them as far away from the crew as possible.

That's generally true, but that's still why we wear the badges.

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