L. J. DVVYER, J. H. MARTIN AND E. W. TITTERTON 



the highest density of stations in the more populous areas downwind from 

 the test site. 



The measured activity of each gummed-film sample collected during the 

 series was converted to the activity at mid-collection time, using the t-^'^ 

 law known to apply to fission-products of this age. Whole-body y-ray doses 

 integrated to 50 years were calculated following Hallden and Harley^. 

 Table 1 gives the accumulated whole-body y-ray dose in milliroentgen for 



Table 1. Whole-body y-ray dose calculated to 50 years for stations in Australia — 

 no correction has been made for shielding 



the series. No correction has been made for the shielding afforded by the 

 normal living habits of man, which can introduce a reduction by an order of 

 magnitude as a correction factor. 



The highest level for the series, 4 mr, was recorded at Bourke and, 

 even with no allowance for shielding, this corresponds to less than 

 0-1 per cent of the natural background over the same period. This is by 

 far the lowest of the maximum dose levels recorded for each of the three test 

 series: — 58 mr at Port Hedland from Operation 'Mosaic' (Monte Bello 

 Islands, May to June 1956), 24 mr at Lismore, Operation 'Buffalo' 

 (Maralinga, September to October, 1956) and 4 mr at Bourke, Operation 

 'Antler'. 



As had been expected from past experience, the air sampling measurements 



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