Dose limits for Volunteers

[R.Smart@unsw.edu.au (Richard Smart)]

At the recent Annual Meeting of the HPS, Toohey and Sparks
presented a paper on "Proposed regulations for radioactive drugs
used in research" (abstract TAM-C6). In this paper they propose the
following limits in adults: 50 mSv committed effective dose equivalent,
500 mSv committed organ dose equivalent, 150 mSv to the lens of the
eye and 500 mSv to the skin from all administrations within 1 year.
Paediatric limits should be 10% of these values.

In Australia, the limits for medical research for the committed 
effective dose equivalent per year are currently 5 mSv in adults,
0.5 mSv in children and 0.1 mSv for babies and infants. These limits 
have been in place since 1984 and are contained in the National 
Health and Medical Research Council publication "Administration of 
Ionizing Radiation to Human Subjects in Medical Research". Any research 
protocols which comply with these limits can be approved by a 
hospital's Radiation Safety Committee and by the hospital's Ethics 
Committee. Any protocols which exceed these limits must be referred to 
the appropriate State radiation control body for approval. In practice 
I have found that 95% of research protocols do comply with these limits 
(or can be readily modified to comply). I therefore find the proposed 
limits for the USA as extraordinarily high. I certainly do not find the 
ICRP 62 limits restrictive, as suggested by Toohey and Sparks in their 
abstract. (I do agree with Toohey and Sparks that the concept of "whole 
body dose" be abandoned for diagnostic nuclear medicine).

The limits in Australia will soon be revised to a committed effective 
dose of 10 mSv over 5 years - limiting any one individual to 
participation in one or two studies over a 5 year period. 

I would be very interested to discover the limits used in other 
countries.
Richard Smart PhD
Department of Nuclear Medicine
St. George Hospital
Kogarah, NSW 2217
Australia
Tel:61 2 350 3112
Fax:61 2 350 3991
Email:R.Smart@unsw.edu.au