The words of Mole (1958) sean as fitting now as they were then written:
Whatever the shape of the enpirically determfned curve,
it ts always possible that the shape of the curve changes at
doses less than the Jowest used. Even {f there were several
dose-levels at each of which the response was no different
fram the base-line contro}, it must be accepted that each of the
ao
measured responses has a statistical error.
The possibility can
never be denied that observations on a much larger scate would
have shown responses really greater than the control.
Thus the
existence of a thresho}d can never be proved by an empirical
dose-response curve.
Equally, of course, for Similar reasons
the absence of a threshold can never be proved.
Thus the
existence or not of a threshold can be determined only on
theoretical grounds.
Along with and because of the uncertainties of radiation effects, a risk
philosophy had to be incorporated into the establishment of radiation protec-
tion hazards (Taylor, 1958).
This philosophy was necessary because radiation
standards, present for severa) decades already, were expressed in terms of
“permissible” doses, which imp) ted the acceptance of some onal}, but undefined
{and undefinable) risk,
Risks moved fran being generally qualitative to being
quantifiable (ICRP, 1966), and have been the subject of elaborate calculations, primarily with regard to safety fron nuclear reactors (US NRC, 1975),
ater
Recognitton that radiation was hazardous resulted in the formation of
several) scientific advisory groups who made recanmendations of limits for
accupational and non-occupational exposures.
fssued in the fone of perfodic reports by:
These recanmendat{fons were
the International Commission on
Radiation Protect ton and Measurements (MW RP}, forming in PMG from an advisory
if
wed reeed ee
"
Radiological Protection (ICRP), founded in 1978; the National Council on