Re: Number of chromosome repairs

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

On Wed, 28 Jan 1998, Mike Grissom wrote:

> I would agree that a firmer 'background DNA repair' rate
> number or well-defined range (allowing for great biological
> diversity) would be very useful in studying such effects
> as chemical carcinogenicity and testing the LNT!  Particularly
> for the human genome...
> 
> At 08:52 AM 1/28/98 -0600, you wrote:
> >	According to Myron Pollycove, who is an expert in this area,
> >chemical and spontaneous processes cause an average of 150,000 single
> >strand breaks and 1.0 double strand breaks in each cell every day.
> >Multiply this by the trillion cells in the body to get the total number.

	--According to Pollycove and Feinendegen, 1 rad of radiation
causes 20 single strand breaks and 0.4 double strand breaks per cell. How,
then, can background radiation be an important contributor to these
processes?