Re: background vs man-made emmissions

["Sandy Perle" <sandyfl@earthlink.net>]

Thank you Tom,

You more eloquent that I was in my response.

One more point, nuclear medicine today utilizes short-lived 
radionuclides, i.e., Tc-99m and Thallium isotopes. These replaced 
the longer half-life radionuclides, such as I-131.

One further point to Norm and others who subscribe to their beliefs 
... why would the half-life have anything to do with whether or not 
there is adverse damage. The physical and effective half-life has 
only to do with removal and remaining activity. How is that different 
than a continual exposure of the same decay products and 
energies. As far as I know, photon, beta, neutron and alpha energy 
are the same, regardless of the source. A 140 keV x-ray is a 140 
keV x-ray, no matter where it originated, and for as long as it 
exists. Only the activity changes.
----------------------------------------------------------------------------------
Sandy Perle					Tel:(714) 545-0100 / (800) 548-5100   				    	
Director, Technical				Extension 2306 				     	
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