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Radiation levels when flying
The aviation industry say that people are exposed to minimal radiation when flying (you could say "they would say that wouldn`t they") but when I took my mum to hospital for radiotherapy there was a notice on the wall stating that 4 hours in a passenger aircraft is the same as a chest x-ray. Who`s correct? Any scientists out there like to enlighten?
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For more on marking an answer as the "Best Answer", please visit our FAQ.Both are pretty small
Radiation dsoes are measured in Sieverts
Flying at 35,000 feet typically exposes you to about 6 microSieverts (that's 6 millionths of a Sievert) per hour
http://www.solarstorms.org/FAAAirlines.html
A chest X-ray exposes you to about 100 microSieverts so about 16 hours flying by my maths.
But the figures will vary depending on the type of X ray and how active the solar radiation is during the "flight".
What is a "safe" level of exposure depends - you could be walking about the street today and get hit by a single decay event from the granite in the pavement and it could give you cancer - but the odds against it are so extreme
The limit for public exposure is 1 millisieverts which is 1,000 Microsieverts
10 x-rays or 160 hours flying
That is still a very low level - the level set down to protect workers is still 20 times higher
200 x-rays worth
Radiation dsoes are measured in Sieverts
Flying at 35,000 feet typically exposes you to about 6 microSieverts (that's 6 millionths of a Sievert) per hour
http://www.solarstorms.org/FAAAirlines.html
A chest X-ray exposes you to about 100 microSieverts so about 16 hours flying by my maths.
But the figures will vary depending on the type of X ray and how active the solar radiation is during the "flight".
What is a "safe" level of exposure depends - you could be walking about the street today and get hit by a single decay event from the granite in the pavement and it could give you cancer - but the odds against it are so extreme
The limit for public exposure is 1 millisieverts which is 1,000 Microsieverts
10 x-rays or 160 hours flying
That is still a very low level - the level set down to protect workers is still 20 times higher
200 x-rays worth
The dosage received during flying increases with altitude (and obviously with duration). For this reason Concorde crews and military pilots both have been the subject of investigations in the past as to the cumulative dosage over the long term. Of more concern are the hours flight attendants work. They are not subject to the restrictions which apply to pilots and due to their lower hourly rates of pay are under more pressure to accept overtime (and even moonlighting for other airlines on off-duty periods).
In the UK we play by the rules - in other countries
1 they don't always and
2 they don't always have rules and
3 even where there are rules they aren't always the same as ours
e.g. FAA regs allow pilots to fly 1000 hours per annum. Most US airlines 'guarantee' flight attendants between 65 and 85 flying hours per month and there are opportunities to work more. (US Dept of Labor).
A further complication is that over pole flights have a radiation burden between 2 and 3 times equatorial level so staff who fly those routes on a regular basis may be picking up atypical exposure.
...and then there are the moonlighters...
on the other hand I agree with Jake - living in a country cottage in Cornwall without a ventilated foundation is much more risky!
1 they don't always and
2 they don't always have rules and
3 even where there are rules they aren't always the same as ours
e.g. FAA regs allow pilots to fly 1000 hours per annum. Most US airlines 'guarantee' flight attendants between 65 and 85 flying hours per month and there are opportunities to work more. (US Dept of Labor).
A further complication is that over pole flights have a radiation burden between 2 and 3 times equatorial level so staff who fly those routes on a regular basis may be picking up atypical exposure.
...and then there are the moonlighters...
on the other hand I agree with Jake - living in a country cottage in Cornwall without a ventilated foundation is much more risky!
237SJ...you may wish to look a this http://www.sciencedir...6a9ca98b1b904e0e3f815
Thanks for your input igtretd. I`m not sure about the statistics though regarding Concorde pilots or any other pilots for that matter. With regards to my original thread, I still stand by my opinion that people that fly as pilots or cabin crew are exposed to radiation that is detrimental to their health.
I disagree 237SJ
The radiation levels that we are talking about here are very very small
If you look at igtrtd's link you'll see that they've presented this evidence despite the fact that the difference they found was *not statistically significant*
In other words they've done the research and basically didn't get the result they were looking for - they still have to write up but basically there's nothing there.
The background radiation in Aberdeen is very high due to all the granite 7.8m Sieverts
That's over a thousand hours flying.
Even when there's a solar flare the flying exposure only goes up by 50%
I am very doubtful that air crew have a significant health risk from low level radiation. I'd be more concerned about exposure to chemicals recirculated in the air
http://news.bbc.co.uk...d_8270000/8270978.stm
If I were working as air crew I'd be more worried about this than low level radiation
The radiation levels that we are talking about here are very very small
If you look at igtrtd's link you'll see that they've presented this evidence despite the fact that the difference they found was *not statistically significant*
In other words they've done the research and basically didn't get the result they were looking for - they still have to write up but basically there's nothing there.
The background radiation in Aberdeen is very high due to all the granite 7.8m Sieverts
That's over a thousand hours flying.
Even when there's a solar flare the flying exposure only goes up by 50%
I am very doubtful that air crew have a significant health risk from low level radiation. I'd be more concerned about exposure to chemicals recirculated in the air
http://news.bbc.co.uk...d_8270000/8270978.stm
If I were working as air crew I'd be more worried about this than low level radiation
jake-the-peg....read the abstract again...
'There was an eightfold significant increase of dicentric chromosomes in the Concorde group.' (relative to the controls)
The finding that was not statistically significant was the difference between supersonic and subsonic crews not the controls (who I assume were neither subsonic nor supersonic crew members)
As to whether this constitues a health hazard isn't a question of who whether you, me or 237SJ 'think' it's a hazard, rather it's a question of doing the study (which may have already been done for all I know). At first sight an eightfold increase would appear to warrant such a study.
'There was an eightfold significant increase of dicentric chromosomes in the Concorde group.' (relative to the controls)
The finding that was not statistically significant was the difference between supersonic and subsonic crews not the controls (who I assume were neither subsonic nor supersonic crew members)
As to whether this constitues a health hazard isn't a question of who whether you, me or 237SJ 'think' it's a hazard, rather it's a question of doing the study (which may have already been done for all I know). At first sight an eightfold increase would appear to warrant such a study.
Here's a full review by the Ocupational and environmental medecine people two years later that cites that first article
http://www.ncbi.nlm.n...25/pdf/v059p00428.pdf
They conclude
Several epidemiological studies point to increased incidence of certain cancers in air crew populations, but the link between cosmic radiation.
I think that it's highly likely that people are jumping to assumptions that this is due to cosmic rays.
Things like long term exposure to certain chemicals can also rapidly raise cancer risks and I would look here before making asumptions about cosmic rays.
http://www.ncbi.nlm.n...25/pdf/v059p00428.pdf
They conclude
Several epidemiological studies point to increased incidence of certain cancers in air crew populations, but the link between cosmic radiation.
I think that it's highly likely that people are jumping to assumptions that this is due to cosmic rays.
Things like long term exposure to certain chemicals can also rapidly raise cancer risks and I would look here before making asumptions about cosmic rays.
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