Re: Aircrew doses

["ALDEN N TSCHAECHE" <XAT@inel.gov>]

I guess my first thought about monitoring such people is: Why, if we are
not going to use the information for control, spend the money to
monitor? My second thought is: We were all upset about radiation
exposure from fallout in the 1950s and 1960s, that contributed much less
dose than airline flying - so much so that we banned in-air testing of
nuclear weapons. I would guess that the collective dose from flying far
exceeds the collective dose from in-air testing. Why then, are we not
banning flying? Aside from the obvious response that, if 5 rem per year
or 10 rem per lifetime doses are so low that quantitative risk should
not be calculated (see the recent HPS position statement on low level
exposures), why did we get so upset about fallout and why should we ban
flying? There is some inconsistency here I think.  Al Tschaeche
xat@inel.gov

*** Reply to note of 05/20/96 09:17
To: RADSAFE --INELMAIL RADSAFE

Subject: Re: Aircrew doses
On Air-Crew "Occupational Exposures"

It has been interesting to follow the thread in the Digests of the last weeks
on the
philosophies of dealing with air crew radiation exposures -- and particularly
the frequent
comments on the potential roles (or non-roles) of different regulatory
agencies and political issues (role of government vs collective bargaining as
control mechanisms), and even a question of why monitor aircrews when you
can't do anything to reduce exposures.   I think it might be useful to close
the thread on a factual basis:

For the record, from Tables 8-6, and 8-7, "Airliner Cabin Environment:
Contaminant
Measurements, Health Risks, and Mitigation Options", DOT-P-15-89-5, by Niren
L. Nagda et al, cabin crew annual average (960 hours/yr) doses for identified
domestic flight routes greater than 3 hours (12.5% of all domestic flights at
the time) were calculated (based on flight plan durations at altitude and
geomagnetic latitude) to range from about 5.9 to 7.3 mSv.   A 1.6 hour
NY-Chicago flight would result in an average crew dose of 5.1 mSv/year.
   Typical international flights of more than 6 hours duration resulted in
annual crew doses ranging from 5.5 to 7.3 mSv.

These are well above the average worker dose at US nuclear power plants.
  The report also assumed a typical frequent flier would travel 480 hours per
year along these routes and hence accumulate half the crew's dose.

I would agree that "Regulation" in the traditional sense is not likely to be
effective for controlling such exposures (which are at least currently within
the limits for occupational dose). However, monitoring of these exposures for
long-distance aircrews is not unreasonable; there are few if any licensees
who would think workers averaging over 500 mrem/year do not warrant
monitoring - if only for their own protection against litigation.  From a
record-keeping point of view, there are existing mechanisms in place for
documenting exposures of transient workers who are at different NPPs at
various times for outages and maintenance activities, so that should not be a
major problem for the airline industry.

These are my views AND those of my boss -- who is also me!

Mort Goldman
(mortgold@aol.com)

ÿ