!! spellx done
188  Radiation and You
     The Washington Post  January 3, 1970

     The precision with which we know the constants of nature is one
of the foundations of an industrial economy.  For example, we know,
and need to know, the speed of light to better than six decimal
places, and the distance from earth to Mars almost as well.  When
engineers face living organisms, however, they must face up to the
cultural shock of certainties, within factors of ten or even a 
hundred, about such vital matters as the health hazards of industrial-by
product radiation.  All of us, in turn, will ultimately suffer from
inaccuracies in such calculations.

     Standards must be set as the basis  of engineering design, from
whatever information is available.  If they are unrealistically 
stringent, they will thwart the development of nuclear energy and we may
stumble in brownouts and choke in increasing air pollution from burning
fossil fuels.  If the standards are too lax, whether from laziness
or exploitation, our own health and the very future of the species are
at stake.

     One of the basic standards is the Federal Radiation Council
guideline of a limit of 170 millirads (0.17 rad) per year for the
general population.  This standard for an allowable exposure to 
additional by-product radiation may be compared with the 100 millirads
from cosmic and natural radioactivity in which we are already immersed.
And an average exposure to about 50 millirads per year from medical
X-rays.  Nuclear energy activities so far, mostly in the form of
strontium-90 fallout, from weapons tests have "used up" less than ten
per cent of the 170 millirad per year allowance.  However, we are on 
the verge of planning large scale expansions of nuclear energy plants
and other uses, and the validity of the standards is bound to be 
crucial to the engineering and economics of this technology. 

     Doctors John W. Gofman and Arthur R. Tamplin of the AEC-supported
Lawrence Radiation Laboratory at Livermore, have sharply attacked the
current standards in testimony before the Senate subcommittee on air
and water pollution.  Their main argument is an analysis of various
data that have been collected on the production of specific forms of
cancer by radiation.  For each of several forms, the "doubling dose"
is about 100 rads.  That is, each rad of exposure should increase the
spontaneous frequency by one per cent of its existing value.  After 30
years exposure at the guideline level, the accumulated extra dose
would be 5.1 rads, calculated to give a 5 percent increase overall in
cancer.

     These figures are probably not very different from the assumptions
that have underlain the policy guidelines.  The logic of these 
standards has unfortunately been contaminated by some unsupportable
optimism that very low doses of radiation may have a less than 
proportionate hazard, and that we might perhaps be able to ignore these
small percentage penalties.  However, as Gofman and Tamplin point out,
this 5 per cent would add up to another 16,000 cancer deaths a year.
Which of these numbers is the proper assessment is a basic issue of 
social philosophy that needs to be examined apart from the technical
arguments that surround it.

     In my first reading I was tempted to quarrel with the argument
that diseases like lung cancer could be influenced by additional
radiation exposure, for we believe that this is mainly caused by
cigarette smoking.  Nevertheless, we must take account of the probable
interaction of radiation with other environmental pollutants, and
with individual variations in susceptibility--which would also nullify
any remaining hope of a no-effect dose.

     The hardest fact we have is the natural exposure rate of 100
millirads.  We can expect to learn more about radiation hazards, and
further news is most likely to be the discovery of now hidden dangers
rather than the converse.  Quite apart from Gofman and Tamplin's
calculations, we should be wise to base our guidelines as a small 
percentage of that unavoidable 100 millirads. 

     Future developments may loosen these standards in either of two
ways.  We might learn how to facilitate the natural repair of radiation
damage.  Or we may continue to poison ourselves so badly with
chemical pollutants that an added dose of radiation would be lost in
the smog, or might even be a happy way out.
-----------------------------------------------------------------------