Study reveals storm cloud radiation fear

[Slats7]

Study reveals storm cloud radiation fear | News.com.au

AIRLINE passengers on planes flying near or through lightning storms could be exposed to harmful levels of radiation, according to new research.

A study in an upcoming issue of the Journal of Geophysical Research - Atmospheres suggests lightning discharges, or a related phenomena known as terrestrial gamma-ray flashes, could expose airline passengers to levels of radiation equivalent to 400 chest X-rays, Fox News reports.

 

[medhead]

Sounds interesting. Given the rarity mentioned in the story I expect the radiation dose from cosmic radiation will be far more significant for the regular flyer. Not sure of the mechanism for producing the radiation. I'll have to have a chat about at work tomorrow.

 

[Slats7]

It sure is an interesting article, something i've never really thought about before.

 

[haydensydney]

Equiv to 400 xrays - that seems quite high.
What are the health implications from high radiation exposure?

 

[2muchplastic]

Equiv to 400 xrays - that seems quite high.
What are the health implications from high radiation exposure?

It's another of those beat ups. Having a CT scan is the equivalent of 290-400 chest xrays, and people don't tend to keel over and die after that.

If you get hit by storm clouds 20 times in 1 flight, then I would imagine you'd need to worry!

 

[samh004]

If you get hit by storm clouds 20 times in 1 flight, then I would imagine you'd need to worry!

If you flew into 20 storms in 1 flight I’m thinking radiation would be the last thing on your mind. Exactly what the pilot is thinking would be the question!

 

[2muchplastic]

If you flew into 20 storms in 1 flight I’m thinking radiation would be the last thing on your mind. Exactly what the pilot is thinking would be the question!

I imagine the first thing that would go through your mind is "What's that terrible smell?", followed closely by "I hope I have some clean clothes in my carry on".

 

[medhead]

It's another of those beat ups. Having a CT scan is the equivalent of 290-400 chest xrays, and people don't tend to keel over and die after that.

If you get hit by storm clouds 20 times in 1 flight, then I would imagine you'd need to worry!

It's not really a beat up. As that article says there is the linear no threshold hypothesis (LNT), what forms the basis of radiation protection practice. LNT gives us a risk factor for longer term outcomes from radiation exposure, based on the observed effects in certain groups of people exposed to radiation. Trouble is the groups of people (cohorts) used to derive the risk factor are groups such as the atomic bomb survivors, nuclear workers, early uranium miners. Basically, people with high exposures. They have then extrapolated the risk for these groups down to 0 radiation = 0 risk.

so what the risk factor says is that for every 1000 mSv of dose one receives in a year, you get a life risk of 5% of dying from cancer derived from that radiation exposure. Now if you lived next door to a uranium mine you would be " allowed" to be exposed to 1 mSv per year as a member of the public. That is a risk of 1 in 13000 of dying from cancer sometime in the next 50 years (so no people don't keel over and die). This is a coughulative risk, so at the end of year 2 you wold have a risk of 2 in 13000. But this risk level has been set internationally because it is about the same risk as being run over by a car as a pedestrian - too low a risk to require controls or intervention.

Note also this is the risk above background radiation dose. Everyone still gets exposed to background radiation. In Australia this averages about 2 mSv per year. Sop live next to a uranium mine and you get 2 mSv from background and upto 1 mSv from the mine (in practice uranium mines don't expose the public anywhere near this much)

So to put this into perspective 2 mSv per year for 50 years means that out of every 13000 people living in Australia 100 are expected to get cancer and die in those 50 years. Compare this to the fact that about 30% of all people get cancer (and die? I'm not sure) during their life. So 3900 people over of 13000 will get cancer and for 100 of those (over 50 years) the cancer is because of background radiation

So for workers the limit is 20 mSv - which that articles says is about the same as 400 chest x-rays, but the risk factor has jumped up here to about 1 in 1000. Again life time risk, so no bodies in the streets. But this is now in the area where people like me get paid the dollars to protect people. Well I could go on but I think that little lecture probably puts the risk into prespective.

I would just mention that we don't police natural exposure like from storms and flying. And in the case of medical exposure the benefits outweigh the risk of the radiation. So you get an x-ray of a broken arm because the benefit of having it fixed outwieghs the minor risk from the radiation.

Of course, CTs are a real new and troublesome area. A chest x-ray will pick up lung diesese (like TB) fine, but these days they do chest CT because it is easier and gives nice pictures (and the cynical would say they get more paid more). But can the extra radiation dose be justified? Also CT, while making bodies, does cause immediate damage. There is a case of about 50 or 100 people would suffer hair loss and burns because of incorrect CT procedures. There was also a recent case of a baby boy getting massive radiation dose due to incorrect CT procedures - again burns and risk of cataracts in 5 to 8 years (iirc). I'll dig out a link when back a work if anyone is interested.

Sorry if I rambled a bit, it is a complex topic

 

[2muchplastic]

It's not really a beat up. .......Sorry if I rambled a bit, it is a complex topic

Medhead, the main reasons I marked it as a beat up are:

1. NoNews have reported it
2. if it were such a major issue, then logic says that there should be a higher incidence of cancers in aircrew than those unexposed in the same way
3. The report is suitably vague stating "What we don't know is how often planes happen to be in just the right place or right time to receive a high radiation dose. We believe it is very rare, but more research is needed to answer the question definitively"

Whilst I don't doubt the danger and risk already known, identified and quantified in the coughulative effects of radiation exposure, this reporting has too much of a vague feeling about it for me to take it seriously.

 

[dajop]

Medhead, the main reasons I marked it as a beat up are:

1. NoNews have reported it

A little sensationalist, yes, all about radiation doses and lightning and then they suddenly jump to the physical effects of lightning, what is the relevance of that to the study being reported??

In May, an Air France jet crashed into the Atlantic Ocean after it was reportedly struck by lightning.
Experts say that lightning alone usually won't bring down a plane, but along with turbulence, thunderstorms and ice, it is a hazard that could be very dangerous to flights.

 

[harvyk]

Me thinks that the pilots would try to get away from storms for other reasons other than a potential extra dose of raditation.

 

[medhead]

Medhead, the main reasons I marked it as a beat up are:

1. NoNews have reported it
2. if it were such a major issue, then logic says that there should be a higher incidence of cancers in aircrew than those unexposed in the same way
3. The report is suitably vague stating "What we don't know is how often planes happen to be in just the right place or right time to receive a high radiation dose. We believe it is very rare, but more research is needed to answer the question definitively"

Whilst I don't doubt the danger and risk already known, identified and quantified in the coughulative effects of radiation exposure, this reporting has too much of a vague feeling about it for me to take it seriously.

Well given the nonews link then it suggests beat up. However, with radiation beat up is usually fear of the unknown/unseeable due to the misinformation spread by the anti-nuclear lobby.

In terms of incidence of cancer in Aircrew, did you read my post? In a short hand way I was trying to say that at these levels of exposure an increased incidence is unmeasurable. That is why LNT still exists today at low doses. Because you need about 5 million people in your cohort to get the statistics to work.

Say that the dose from one storm is about the same as the worker dose limit, as per the article you quoted. LNT says that anyone exposed to that much radiation in one year has 1 in 1000 chance of fatal cancer at sometime in the next 50 years. In those same 50 years 330 people are going to get cancer (possibly fatal). So the 1 person that gets cancer because of radiation from a storm cannot be distinguished from the 329 other people who get cancer. So the reason you don't have a higher incidence of cancer in flight crews due to radiation is because you can never know if the cancer was caused by radiation. It is swamped by the vast numbers of cancers from other causes.

having said that increase incidences of breast cancer has been noted in female flight crew and there are some suggests that is due to cosmic radiation (i.e. background non storm radiation).

The statements also have to be suitably vague because there are a lot of ifs involved here. Does the aircraft fly in a storm, does it fly close enough to a radiation producing event, does it get exposed to that radiation produced. Lots of questions. Add to this that WHO have estimated that flight crews flying 600-800 hours are exposed to a dose of 2 to 5 mSv per year. This is about the same (or a bit less than) the storm produced radiation exposure. So aircrew are already getting a bit of a dose from flying, but still with an unmeasurable risk factor. The obvious rarity of a storm event and all the "ifs" mean that any annual storm related exposure will be minimal compared to the other exposure. Another reason why there is no observed increase in cancer incidence.

But of course, I agree that it can't be taken seriously. just outlining why they can get away with this type of story - it's based on published fact, but it is still a beat up. The anti-nuke groups have been getting away with this sort of rubbish story for decades to oppose uranium mining and nuclear power. Strangely, they ignore the fact that aircrew are getting about the same exposure as the average uranium miner, from cosmic radiation.

 

[2muchplastic]

...In terms of incidence of cancer in Aircrew, did you read my post?

I did read your post medhead and even understood (I think): Because of the coughulative, long term effect of radiation exposure it would be impossible to distinguish, statisically speaking, the incidence of cancers in aircrew that are related directly to this type of exposure in the study because of the low numbers of people involved, compared to a natural background incidence of cancers. Combined with the LNT theory that, in simple terms, no dose is safe as such, you just need a statistically large enough sample size to be able to measure it. (Yes?)

I was just trying to be a little more extreme, in a flippant kind of way, and attempting to say that if there was such a huge risk, then no pilot would ever see 60, and half of them would spend their last moments lying on the floor in F with bleeding gums and their hair coming out.
(Yes, I know there's a big difference between 3 mSv and 100 Sv and the effects of each, and trying for comic effect on such a subject is a bit of a poor show....)

A little OT, but I was interested to hear your point about the number of people damaged by CT scans, I don't believe that is something that has even been publicised. The cases of radiotherapy "mishaps", for want of a better word, where patients have been given too high a dose almost make front page news, but those cases you're describing certainly haven't (unless they are very recent - since wifey dearest left the medical profession a few years ago and she doesn't bring the gossip home any more)

 

[medhead]

Yes of course I knew you read the post, I was also trying to be flippant. Sorry.
But funny (as in stupid me) that I didn't pick up the same from you

In those other cases with CT it is mainly the new generation of CT scanners with multi-slice, the largest I've heard of is 320 slice CT. Also digital or computer imagining is an issue because the software corrects the image, so there is a tendancy to just apply settings that the sales reps use. This still produces decent imagines, and the radiographer may never realise that they are overexposing patients or even underexposing, which can be an issue because even with the correction potential problems will not be revelled by the image.

Here is a link,
U.S. probing more cases of CT radiation overexposure | Reuters

and another (this is the original story I was thinking of)
http://www.healthleadersmedia.com/c...T-Radiation-Overexposure-to-206-Patients.html

and a special case of an excessive number of exposures (sorry can't paste a link without signing up to AuntMinnie website)

California RT gives deposition in CT overdose case
By Donna Domino
AuntMinnie.com contributing writer
December 10, 2009

The California radiologic technologist accused of operating the CT scanner that delivered a massive radiation overdose to a 23-month-old boy in 2008 testified last week that she only pushed the CT scan button a few times, and she doesn't understand how the toddler received 151 scans in a single imaging session.

Dr. Fred Mettler, a radiation injury specialist at the radiology department of the University of New Mexico in Albuquerque, estimates the boy received the following radiation doses: 5.3 Gy to the brain and salivary glands, 7.3 Gy to the skin, and 1.54 Gy to the lenses of both eyes, according to Stockett. The child will probably develop cataracts within three to eights years, Mettler concluded.

If your really interested I'll post the full story.