[ RadSafe ] Fwd: Pilots UV-A radiation exposure
Hans J Wiegert
hjwiegert at gmail.com
Fri Dec 26 16:51:53 CST 2014
Joe,
You asked some very good questions and I need to clarify a few things.
1. The badges were not neutron sensitive. I worked with electron beam
accelerators and we were only interested in X-Ray and Beta (electrons)
radiation.
2. The film badges were read monthly. The OSL badges were initially also
read on a monthly bases to get a better feel for the increased sensitivity.
After about two years the reading frequency was changed to bi-monthly as
recommended by Landauer.
3. Some of the miles were indeed extra credit. My travels actually
started in 1975 and only after a job change in 1984 was I issued a
radiation badge. My "guesstimate" is that the actual miles flown are
somewhat between 1.75 million and 2 million miles.
4. The frequency of my trips changed with the project schedule. There
were years were I traveled about every six weeks and years were I only had
four or five flights. Most of the flights were long haul (10 hours or more).
5. The old film badges had a lower limit of 50 mrem, The OSL badges went
as low as 1 mrem for X-ray and 10 mrem for Beta. (
http://www.landauer.com/uploadedFiles/Healthcare_and_Education/Products/Dosimeters/LuxelSpecifications.en-US.pdf
)
6. The badges were used for work. Typically equipment operators left
their badges on a rack at work. Our engineering group took the badges home
since we were responsible for Radiation Safety at a number of facilities
with a 50 mile distance; leaving the badges in the office was not practical
if there was an after hour emergency. To prevent accidental exposure at
airport security checkpoints I always clipped my badge on a belt loop or
shirt pocket. This led to some interesting discussions after 9 - 11 with
TSA personnel; you'd be surprised how often they wanted me to send the
badge through the X-ray unit! I don't remember any significant occupational
exposure. Anything above 100 mrem would have been flagged for an
investigation. I also do not recall a case were I could correlate a minor
reading to a trip. The control badges were always kept in a supervisor's
office to accurately record the background radiation at a particular
location.
7. A 200 mrem gamma exposure would have certainly been noticed. As
stated above, anything 100 mrem or over was flagged for investigation. The
few times that happened was were someone wore the badge during a medical
procedure or some other "accidental" situation. Sometimes "exposures"
required quite a bit of "detective" work, but this is subject for a
different discussion..
As a side note, are you aware that the "Concorde" was equipped with a large
volume ionization chamber? On one of my trips to the UK I visited "The
Imperial War Museum" in Duxford and walked through a "Concorde" prototypes
on display there. Got a picture of it in case you are interested. The
flight crews for the "Concorde" were classified as "radiation workers" and
wore personal dosimeters. The ion chamber was used to monitor the radiation
levels in the cabin and in case of increased sunspot activity (and
radiation levels) the plane had to descend to a lower altitude to meet the
exposure limits for the passengers as "members of the general public"
I did not bother to get a copy of my last exposure record; there was
nothing to be concerned about and I was not looking for any work requiring
this information. After your e-mail I requested a copy from my former
employer and don't mind sharing this with you if you are interested. Also,
feel free to contact me directly at my personal e-mail: hjwiegert at gmail.com
Sorry for not responding any sooner, but Christmas with the grand kids had
a "slightly" higher priority!
I hope everyone had a good Christmas holiday and wish you all a Happy New
Year!
Best Regards,
Hans
*Retirement is, when the only day you have to set your alarm clock is
Sunday - so you are not late for church!*
On Sun, Dec 21, 2014 at 1:58 PM, <jjshonka at shonka.com> wrote:
>
> Hans
>
>
> I am quite interested in your badge results, and what would be a
> significant radiation exposure. You have an unusually high number of
> frequent flyer miles. If we assume total neutron plus gamma of 500 mrem
> (5 mSv) per 100,000 frequent flyer miles or per year, and 15 rem over a 3
> million mile or 30 year career, I have the following questions: (1) were
> your badges neutron sensitive (80% of GCR dose is due to neutrons)?; (2)
> how often were they read out (quarterly, monthly?); (3) were many of your
> miles extra credits rather than actual miles flown (e.g. first class gets
> 2X miles)?; (4) were your miles collected evenly or did you travel more
> extensively during some fraction of your career?; (5) what would you say
> the reporting limit or detection limit of the badges was (e.g any reading
> less than 10 mrem (0.1 mSv) reported as 0)?; (6) were your badges used for
> work and did they have measureable exposure from sources other than
> background plus your flight time?
>
>
> Ed Bramlitt and I have a note in the January, 2015 issue of Health Physics
> that discusses intermittent sources of exposure to aircrew, including solar
> proton, neutron and gamma events and terrestrial gamma flashes. About 1%
> of the 1200 Terrestrial gamma flashes that are large enough to be detected
> by satellites that occur each day (world-wide) approach estimated doses in
> aircraft of up to 30 to 100 mSv, for example. Although rare, these likely
> would have been observed on your badge. The more numerous dose of 10 mSv
> or greater (my estimate of the lower limit of detection for the GBM
> detectors on board FERMI) might also be detectable, however, presumably
> even more numerous but undetectable lower dose TGFs (below 10 mSv) might
> not be detected. I am interested in how large one of those events could
> have been without your noticing an unusual reading.
>
>
> I assume the background control badges were at your place of employment.
> Finally, (7) For example, if you typically had 12 flights per quarter, and
> one of those flights encountered a source that provided 1,000 mrem (10 mSv)
> 80 % of which was neutron and only 200 mrem (2 mSv) was gamma, would you
> have noticed it as an unusual badge reading?
>
>
> Joe Shonka
>
>
>
>
>
>
> Sent from Windows Mail
>
>
>
>
>
> From: Hans J Wiegert
> Sent: Saturday, December 20, 2014 7:18 PM
> To: The International Radiation Protection (Health Physics) Mailing List
>
>
>
>
>
> For what it's worth.
>
> I am not so sure about this. During my career I traveled almost 3 million
> miles on various airlines with my seating preference being a window seat.
> Never noticed anything like this. As a side note, on almost all of those
> trips I carried a film badge on me and in recent years the Landauer Luxel
> OSL badge. The badges never showed any significant radiation exposure.
>
> Best Regards,
>
> Hans
>
> *Retirement is, when the only day you have to set your alarm clock is
> Sunday - so you are not late for church!*
>
> On Thu, Dec 18, 2014 at 2:19 PM, Chris Alston <achris1999 at gmail.com>
> wrote:
> >
> > This is easy to believe. I, as a passenger, have gotten a pretty good
> > tan, mostly on one side of my face, on just one trip from Seattle to
> > San Diego. Fortunately, I had a window seat on the other side of the
> > aircraft (DC-9 family, for whatever it is worth) on the northward
> > return flight, to "touch up" the other side of my face, else I would
> > have looked like that arch-criminal in the Batman comics.
> >
> > Cheers
> > cja
> >
> > On Wed, Dec 17, 2014 at 8:36 PM, ROY HERREN <royherren2005 at yahoo.com>
> > wrote:
> > > Hopefully the following isn't too "off topic", given that the article
> is
> > dealing with UV-A radiation.
> > >
> >
> http://media.jamanetwork.com/news-item/airline-pilots-can-be-exposed-to-cockpit-radiation-similar-to-tanning-beds/
> > > Airline Pilots Can Be Exposed to Cockpit Radiation Similar to Tanning
> > Beds
> > _______________________________________________
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