In-flight radiation -Reply

[Mutty Sharfi <SHARMM@doe-md.gov>]

Silvia,

To your question of how flight crews can be protected, the main
principle in radiation protection is not to be in the path of it.  Therefore if
you know the average exposure per flight (probably more like per hour
of flight and altitude) one can adjust flight crew schedules (by reducing
flight time) to minimize the potential of overexposure.  It is to my
understanding that a single cross country flight (LA to NY) is only a
couple mrem.  Therefore, to reach the DOE limit of 5 rem (5,000 mrem), a
flight crew would have to fly almost a 1,000 or so flights which is not to
common (3 flights per day 365 days a year).  However, ACLs
(Administrative Control Limits) are set sometimes up to a factor of 10
below the DOE limit to ensure compliance (2,000 - 500 mrem).  Therefore,
if an ACL of 500 mrem was used, it is very possible to exceed the ACL. 
I would remind you that passing the ACL is not considered to really
increase in risk of cancer to the individual (but that is another debate; the
debate on LET).  The DOE dose have guideline for planned exposures up
to 25 rem (25,000 mrem).   

Another interesting note:   

The most interesting part of flight crews and radiation is on pregnancies. 
To my understanding the time at which a fetus is most sensitive to
radiation is the second trimester. I have been told by flight attendants,
that the airlines warn passengers about the risk to exposure to all
pregnant women (pointing out the point about the second trimester), but
when I comes to their own flight crews, a woman cannot (I probably
shouldn't say cannot, maybe just that they are not compensated if the
take off) take off till she is in her third trimester (meaning she must fly
and expose the fetus during the second trimester; the time at which the
fetus is most sensitive to radiation).  Don't know if this is true for all
airline or what, just what I was told.

Well, I hope this helps you.  Enjoy.

****************************************************************************************The opinions expressed above are mine alone and my not represent the
opinions of my employer of the DOE.
****************************************************************************************

Mutty Sharfi
Internal Dosimetry
Mound Site 
BWXT of Ohio
sharmm@doe-md.gov 


>>> CARFORA SILVIA <atomica10@home.com> 11/14/99 10:10pm >>>
Hello, 

I read the Radsafe archives on in-flight radiation and I think that crew
members should be aware of health risks associated with radiation
exposure.  
Dose monitoring is important, but how can flight crews protect
themselves from radiation?
Can individual radiation dose be lowered?
How can their work environment (the aircraft cabin) be used to help
lower the levels of radiation, crews are normally exposed to?

I am a student researching in-flight crew radiation exposure and the
related health risks.
Any information would be greatly appreciated.

Regards,

Silvia Carfora
atomica10@home.com
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