Re: Number of chromosome repairs

[Bernard L Cohen <blc+@pitt.edu>]

	There have been published critiques of the numbers in the Billen
paper. The numbers I quoted from Pollycove take this more recent info
into account.

Bernard L. Cohen
Physics Dept.
University of Pittsburgh
Pittsburgh, PA 15260
Tel: (412)624-9245
Fax: (412)624-9163
e-mail: blc+@pitt.edu


On Tue, 27 Jan 1998, Andrew Karam wrote:

> >Dear Radsafers:
> >
> >A staff member has asked the following question:
> >
> >What is the average number of chromosome repairs per day?
> >
> >I guess around 100K, but would appreciate something a bit
> >more scientifically concrete.
> >
> 
> According to Billen (Spontaneous DNA Damage and Its Significance for the
> "Negligible Dose" Controversy in Radiation Protection, Radiation Research,
> 124 pp 242-245, 1990) there are about 10,000 measureable DNA modification
> event per hour in each mammalian cell due to intrinsic causes (roughly
> quoted).  He goes into more detail as to the source of these, but he
> equates this to the damage done by about 80 cGy per hour.
> 
> Hope this helps.
> 
> Andy
> 
> The opinions expressed above are well-reasoned and insightful.  Needless to
> say, they are not those of my employer. (with apologies to Michael Feldman)		
> 
> Andrew Karam, CHP  (karam.1@osu.edu)		(614) 292-1284 (phone)
> The Ohio State University 				(614) 292-7002 (fax)
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>