35. 



of the activity in the environment, there is the likelihood that low 

 levels during the lag period maybe interpreted as an overall measure 

 of the hazard level. 



Because many marine organisms have the ability to concentrate 

 within themselves substances that appear in their environment, they 

 stand out as the part of the marine system best suited as an indicator 

 of radioactive contamination. This appears to be especially true of 

 bottom organisms. There is merit in the suggestion that bottom organ- 

 isms, oysters or clams for example, be introduced into an area and 

 then used as indicators of contamination levels. 



The results of a recent survey of the Pacific coast disposal areas 

 (5), in which dumping has gone on for about ten years, suggest first 

 that no gross contamination of the environment is now evident, and 

 second, that in bottom deposits low level contamination by fission 

 products is difficult to detect and measure against the background of 

 radium and its daughter products. 



Our recommendations concerning the quantities of activity, rates 

 of disposal, separation of disposal areas, and package characteristics 

 can be criticized as being extremely conservative, especially when 

 compared with existing British practices and in the light of preliminary 

 studies of the disposal areas of the U. S. Pacific coast. We justify 

 these conclusions, first of all, on the grounds that disposal practices 



