In-Flight Radiation

[ROBBARISH@AOL.COM]

Dear List:



There is quite a lot on this in the RADSAFE archives. Also, a look at the Ask 

the Expert answers at the website of the Health Physics Society will reveal 

more.



Since I wrote the articles in Health Physics referred to here and also the 

recent paper in Obstetrics and Gynecology that prompted this thread, let me 

reiterate a few key points.



The FAA did classify flight crewmembers as occupationally exposed individuals 

in 1994. Advisory Circular AC 120-61 is quite clear on the subject. It can be 

accessed at:





http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/7E5699223F365C78862569BC0057D047?OpenDocument



Notice that that the document refers to the Presidential Guidance on 

Radiation FOR OCCUPATIONAL EXPOSURE (emphasis mine) which is used by all other Federal 

regulatory agencies in maintaining a uniform standard of permissible 

exposures for radiation workers. The principal difference is that the FAA has chosen 

to make their comments on the subject advisory, not regulatory.



With respect to the software used to calculate in-flight doses on a 

trip-by-trip basis, the program is called CARI-6 and can be accessed at the FAA 

website:



http://jag.cami.jccbi.gov./cariprofile.asp

  

I reviewed an earlier version in Health Physics a few years back.  For 

professional flight crew members, the variations of altitude and latitude tend to 

average out over a large number of trips so entering a "generic" flight plan 

pretty much gives the accumulated dose. For individuals taking a flight or two, 

knowing the altitude changes and durations along the route is a matter of some 

speculation unless you cozy up to the captain for the information. But for a 

few flights, the total dose really doesn't matter anyway. 



As Joyce May said in her presentation to American Airlines that appeared in 

the press a few days ago, the real concern is from aircrew who have never been 

given specific information about in-flight radiation even though every other 

regulated employee, often receiving far less dose, is required to have some 

information in order to make educated decisions about the acceptability of their 

exposures. 



I think that all sensible RADSAFE list members would agree that at the levels 

of exposure encountered in an airplane the risk is not great, and may indeed 

be nonexistent if the LNT model is invalid. But I believe that all exposed 

workers have the right to know something about the nature of their exposure in 

order to make an informed decision about those risks. As we all might agree, 

knowing virtually nothing about radiation risk leads to far more anxiety and 

confusion than having a good background understanding of the subject. That's why I 

wrote my book The Invisible Passenger. The paper in Obstetrics and 

Gynecology. "In-Flight Radiation and Pregnancy" can be accessed at their website and 

downloaded for the usual few-dollar fee if any of you want to read it.



http://www.greenjournal.org/cgi/content/abstract/103/6/1326?maxtoshow=&;

HITS=10&hits=10&RESULTFORMAT=&author1=Barish&searchid=1089419691972_247&

stored_search=&FIRSTINDEX=0&sortspec=relevance&journalcode=acogjnl





Regarding the Concorde radiation exposures, the following publication will be 

of use:



British Airways measurement of cosmic radiation exposure on Concorde 

supersonic transport. Health Phys. 2000 Nov;79(5):545-6. 



The following link has a number of other interesting papers on this subject. 



http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Display&;

dopt=pubmed_pubmed&from_uid=11045527





I get RADSAFE as a digest, so I may be behind in reading items that have been 

recently posted.



Rob Barish

robbarish@aol.com