Re: Dirty bombs

[Steven Dapra <sjd@swcp.com>]

December 20, 2002



	A few more comments on the Federation of American Scientist's (FAS) views

about dirty bombs.



	These views will be found in testimony by FAS president Dr. Henry Kelly

delivered before the Senate Committee on Foreign Relations on March 6,

2002.  Dr. Kelly's testimony takes up 8 and one-half pages, and is

accompanied by five pages of area maps of New York City, Washington D. C.,

and the areas the FAS claims would be contaminated by the dirty bombs.

According to Dr. Kelly, the analysis he presented in his testimony was

prepared by Michael Levi, Director of the Strategic Security Program at the

FAS, and by Dr. Robert Nelson of Princeton University and the FAS.  Levi

and Dr. Nelson examined the alleged effects of a cesium bomb and an

americium bomb detonated in Washington, and a cobalt-60 bomb detonated at

the southern tip of Manhattan Island.



	In his posting of Dec. 19, Richard L. Hess suggested that the

contamination contours on the FAS maps were based on normal LNT

calculations.  He is probably correct.  Speaking about gamma rays near the

beginning of his testimony, Dr. Kelly said, "Fatalities can result from

very high doses.  Long-term exposure to low levels of gamma rays can also

be harmful because it can cause genetic mutations leading to cancer.

Triggering cancer is largely a matter of chance:  the more radiation you're

exposed to, the more often the dice are rolled.  The risk is never zero

since we are all constantly being bombarded by large amounts of gamma

radiation produced by cosmic rays, which reach us from distant stars.  We

are also exposed to trace amounts of radioactivity in the soil, in building

materials, and other parts of our environment.  Any increase in exposure

increases the risk of cancer."



	I am not an HP, but this sound to me like LNT.  It seems likely to me that

Drs. Kelly and Nelson, and Mr. Levi have all bought into LNT, and if this

is so they would naturally use LNT calculations.  Dr. Kelly says nothing

about how the FAS analysts derived their contour lines, but he does note

that "[t]he EPA has a series of recommendations for addressing radioactive

contamination that would likely guide official response to a radiological

attack."  The FAS analysts are probably using EPA guidance on cancer deaths

as well, from the ubiquitous Federal Guidance Report 13.



	The Kelly testimony did include some recommendations such as reducing

access to radioactive materials, expanded use of radiation detectors and

improving detectors, and better disaster response training.



	Dr. Kelly's testimony with its area maps can be found on the FAS web site

www.fas.org.



Steven Dapra

sjd@swcp.org





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