516 



It may be added that, the total health and environmental impact due to the 

 addition of all the "artificial" radioactive materials to the sea is, in 

 turn, much less significant than that of the naturally occuring 

 radioactivity (see previous calculations), which in turn, is far less 

 significant than the impacts due to the stable (non-radioactive) toxic 

 elements in seawater. 



Some have suggested that, since measurements of radioactivity in the 

 immediate vicinity (within a few centimeters) of a ruptured container were 

 elevated compared with the levels of radioactivity in the general area of 

 the Farallons, a problem must exit. The fallacy of this conclusion is 

 best described by analogy. 



Suppose one were to visit a large city, measure the height of the first 

 person he encountered, record the height as say, five feet, and leave to 

 return the following year. On the second visit the same procedure is 

 followed by measuring the height of the first person met and recording the 

 height to be six feet. From such analysis, can one conclude that the 

 average height of the city's residents is increasing at the rate of one 

 foot per year? The absurdity of such a procedure is increased if, on the 

 second visit, one were to seek out the tallest person before measuring the 

 height. 



The point is that from the data available, one cannot determine that 

 levels of radioactivity are increasing. On the other hand, the data 

 available do support the conclusion that levels of radioactivity are 

 simply too small to present a significant hazard. 



In general, the interpretation of data such as that reported in the 

 various EPA reports must be done with caution. It is not unusual that a 

 set of environmental samples taken from the same population, or 

 "statistical universe" may vary by orders of magnitude in their 

 radioactivity content. Given the nature of this variance, it takes a 

 large number of samples and sophisticated statistical methods to 

 determine significant differences between sample sets, much less cause and 

 effect relationships. To reach a firm conclusion on the basis of a single 

 data point is problematic since it can result in gross misinterpretation 

 of the situation. 



Perspective on Units 



Since many people are relatively unfamiliar with the physical units of 

 environmental radioactivity, it is important to offer perspectives on the 

 meaning of these units when presenting an analysis. 



For example, granite is a material with which most people are familiar. 

 Many public and private buildings are constructed with granite, and man 

 has lived, and even thrived with granite in his immediate environment 

 during his entire existence. Granite contains uranium and its decay 

 products, just as other crustal materials do, as trace constituents. The 

 average granite contains some 6.7 parts per million uranium. When the 

 alpha activity of the uranium and its daughter products are calculated, 

 the result is some 18,000 picocuries of alpha radioactivity per kilogram 

 of granite. When this value is compared to the aplha activity (Pu 239 & 

 240) of ocean sediment at the Farallon dumpsite, the latter values are 

 found to be extremely small. 



