Medical examination for a radiation worker

[John Lam <lamhc@hkusua.hku.hk>]

Can anybody comment on the above topics?
There is still a strong debate amongst staff of different fields within the
hospital services on this issue. Staff working with isotopes, like those
working in the nuclear medicine,radiographers, doctors, scientific
officers, physicists. These people have exposures not only in external
radiation but also internal exposures. But since not many facility can have
in-vivo assessment of dose in the mean time. Only the usual film badge
method is used.
There seems to be argument how to define what a radiation worker is ? some
people make the situation complicated by defining another term like
"classified radiation worker" and limit the medical examination done to
that sort of staff category. The definition is still vague by "classified
radiation worker are those people likely to receive 3/10 annual dose,
taking 100mSv in 5 years as average ==> 20mSv/year , 3/10 dose will then be
6mSv/year" but the phase "likely to receive" for me is still very vague and
not sound scientific enough, that in fact leave the debate endless. If that
is based on the historical records of dose measured for an old staff, by
probability aspect, the history may not be any indication in the future
exposures. If by any person (for a department head to judge it, very
subjective! it tends to vary from one department  to another?)
There is still argument on what examination is really needed, eg,. like
blood counting, no. of red corpuscle, no. of white blood cells etc. 
Are there really any effective means of medical examination which can make
it relevant to the radiation induced effect to human body, the threshold of
dose like 6mSv or 20mSv in those detections?
The above discussion stands as a technical viewpoint only, of course this
issue can also be solved in a legal law or radiation ordinance aspect, but
people may pretend to go against it as a technical man. I 

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