Re: High Altitiude Exposures

[gu9@cosmail1.ctd.ornl.gov (Robert J. Gunter)]

The problem of measurement is the same in this case as in high energy
accelerator fields.  The problem is, how do you build a detector that will
measure the high E particles contributing to dose.  Next you have to fit it
onto an airplane where places to put it are at a premium, then you have to
read the results.

The limiting population is pregnant flight attendants (500 mrem/gestation
period).  How do you treat that case.  Apparently, the international routes
where you can get dose pay better.  If you were to tell a flight attendant
they can't travel this route while they are pregnant, you impact their
career (remember Johnson Controls).

There are some people looking into this.  I think there were some articles
in the HP Journal from studies done in Australia in the past couple of
years.  In addition, the FAA is also interested.  

A side bar to this is that the Concorde has radiation detectors on it.  I
cannot remember what they alarm at but I think there are 2 setpoints with
one at about 200 mr/hr. I think they are ionization chambers.

Check out this paper:

DOT/FAA/AM-92/2  Radiation Exposure of Air Carrier Crewmembers II.

Available to the public through the National Technical Information Service,
Springfield, VA 22161

Here's an excerpt:  

On some flights the galactic radiation received by an unborn child may
exceed the recommended limits (ICRP limits of 2 mSv during the term of
pregnancy), depending on the woman's work schedule.  For example if she
worked 70 block hours a month, exclusively on the filght with the highest
dose rate per 100 block hours (Athens Gr - New York) her monthly dose at the
current stage of the solar cycle would be 0.56 mSv (56 mrem).  

Block hr= equals the time a plane spends between gates of an airport.

At 02:03 PM 12/11/95 -0600, you wrote:
>Chat has been down to a minimum.  Everyone must have taken an early holiday.
>
>A while back, a thread ran on exposures to flight attendants and pilots.
>The mean exposures were between 1-3 mSv/year.  Hmm...this sounds like
>occupational exposure.  In the world of DOE, these individuals must be
>monitored for exposure because they exceed 100 mrem/year under typical
>conditions (10CFR835).  
>
>Where is the dosimetry?  Where are the exposure records?  Navy Nukes are
>badged...aren't they?
>
>I had the luck of living next to a couple of flight attendants
>(stewardesses-not politically correct).  No badges...no RAD training...  How
>do these folks get by the regulators?
>
>Flying the Concord surely allows a larger dose.  I understand that it is
>less time, but the flight is much higher.  Now we're talking high energy
>physics (>20Mev neutrons and much higher energy cosmic rays-accelerator type
>stuff).
>
>Do I fly or take the train with John Madden and his All Madden Team?
>(please delete my message on responses and comments)
>
>*********************************************************
>DISCLAIMER!!!DISCLAIMER!!!DISCLAIMER!!!
>The opinions expressed may not be those of my employer.
>
>Matthew Williamson
>USDOE
>Environmental Measurements Lab
>376 Hudson Street
>New York, NY  10014-3621
>
>tel:   212-620-3793
>fax:  212-620-3600
>email:  mattw@eml.doe.gov
>
>"I believe that many children are born with an inquisitive mind, the mind of
>a scientist, and I assume that I became a scientist because in some ways I
>remained a child." 
>- Leo Szilard
>*********************************************************
>
>
>
Robert J. Gunter
Lockheed Martin Energy Systems, Inc.
Oak Ridge National Laboratory
P.O. Box 2008 
Bldg: 105MIT Mail Stop 6494
Oak Ridge, TN 37871-6494
PH:  (615) 576-6317
FAX: (615) 576-8593
email: gu9@cosmail1.ctd.ornl.gov