Re: Low-Level radiation

[Jim Muckerheide <jmuckerheide@delphi.com>]

Thanks, John:

> Try the following web site address:
>
> http://www.ireland.com/newspaper/ireland/1999/0721/hom13.htm

See also below the continuing campaign to get rad protection involved in
air crews, the 6 mSv limit, and continuing pitch to the gullible public
of attribute lung cancer to radon:

The Irish Times
                                                               Thursday,
July 22, 1999

                                          Study measures air crew
                                            exposure to radiation

                                       By Dick Ahlstrom, Science Editor

Air crews working on transatlantic flights receive more
exposure to radiation than the typical nuclear power-plant
worker, according to new research, and twice the exposure of
ground-based staff.

The exposures come from naturally occurring cosmic ray
radiation which reaches us from deep space, explained Prof.
Denis O'Sullivan, of the Dublin Institute for Advanced Studies,
who was in charge of the EU-funded research effort. "I was
asked to co-ordinate the research because I have a
background in cosmic rays."

The project involved scientists in Britain, Germany, Sweden,
Austria and at CERN, Europe's high energy physics research
centre. Special equipment was placed on short- and long-haul
flights by participating airlines including Aer Lingus, and
radiation levels were measured. Prof. O'Sullivan presented his
research yesterday at the 11th International Congress of
Radiation Research, which was organised by the Dublin
Institute of Technology.

"Cosmic rays originate outside our solar system and they
envelop the whole solar system," Prof. O'Sullivan said. They
are "very high energy particles" which break up when they
strike the atmosphere or other materials and cause a cascade
of particles which together cause the ionising radiation
exposure.

We are all bombarded by cosmic rays all the time but the
thicker sea level atmosphere mops up more of them than is the
case for high-flying aircraft. Radiation is measured in
thousandths of Sieverts (mSv) and an average ground
exposure from all natural radiation sources might reach 2mSv a
year.

Transatlantic pilots and attendants flying 600 hours a year
would be exposed to double this amount and staff working
long-haul flights to South America or South Africa might reach
three times this amount, Prof. O'Sullivan van said. Short flights to
London or the Continent would add about one mSv to the
natural background levels over the course of a year.

"Air crews are the most exposed to radiation of any
occupation, even more than radiation workers," he said. "There
is obviously concern for pregnant aircrew."

It was still not considered a major problem, he added, although
the European Commission had put together regulations to be
introduced next year which would limit the exposures for air
crews. It proposes an exposure ceiling of six mSv a year,
reduced to half this amount for pregnant staff.

Prof. O'Sullivan said the research could not have been done
without the involvement of CERN, which provided baseline
measurements which were then compared with the data
collected during flights.

Conference delegates heard a presentation on the naturally
occurring radioactive gas, radon. Dr Evan Douple of the US
National Academy of Sciences said research indicted that 10
per cent of all lung cancer deaths were caused by exposure to
radon, making it the second most important cause of lung
cancers after smoking.

About 1,500 people die of lung cancer each year in Ireland
and so about 150 deaths could be attributed to radon
exposure.


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