Each
state in Australia has legislation relating to protection against exposure to ionising
radiations. Permissible levels of exposure to ionising radiation and radioactive materials
in this legislation are generally based on the recommendations of the Australian National
Health and Medical Research Council (NHMRC) and Recommendations of the International Commission
on Radiological Protection (I.C.R.P).
The
Dose Equivalent Limit for adults exposed to ionising radiation during their work is 20
milli-Sieverts per year. This is (effectively) a whole body dose, and the dose limit for
individual organs (if irradiated singly) may be somewhat higher. No special provision is
made for women of reproductive capacity, but once pregnancy is discovered, supplementary
dose limit of 2 mSv should apply to the surface of the abdomen for the remainder of
pregnancy. For the member of public 1 milli-Sievert per year is the annual limit.
If radiation
exposure does not exceed the levels defined above, then the risk to radiation workers and
the general public has been estimated to be small and within acceptable limits. As an
additional precaution, however, the ICRP has recommended that all exposures be kept as low
as reasonably achievable, economic and social factors being taken into account (the ALARA
principle). This policy has been adopted in Australian National Health and Medical
Research Council recommendations and in various State regulations.
Careful guidelines
need to be followed while administering radionuclides to pregnant women.
Guidelines
for Administration of Radionuclides to Pregnant Women
