[ RadSafe ] Chris Busby
Otto G. Raabe
ograabe at ucdavis.edu
Fri Apr 22 12:13:58 CDT 2011
At 02:17 AM 4/22/2011, Dr. Busby wrote:
>1. Its is a comparison of two probabilities. "Very small" is not a
>quantitative measure. You have to compare the probability of a Y90
>decay in 12 hours with the probability of the same cell getting 2
>hits in 12 hours from the same dose of external radiation. However
>small the absolute probability for one atom sequence the number of
>atoms involved is very large (as the overall contamination goes
>up) and so the product gives you the probability of a second event
>in the body/tissue. The probability of a second event from external
>is vanishingly small though calculable. There are 10^13 cells. The
>probability of two tracks from external is 1 in E-26. The
>probability from two tracks from Sr90 Y90 is a lot less (12 hr
>period and 64hr decay so the enhancement is about E+22 for a simngle
>atom, decay internal vs external.
>
>2. Not if they are bound to the DNA in condensed form. Furthermore,
>there is the ionisation change at the decay locus from
>transmutation. Sr++ to Y+++ is an ionisation. Then Y+++ to Zr is
>also an ionisation from transmutation redox. And even if it is very
>small (you can work it out on complete randomness into 4pi) it is
>not as small as E-26 and there are a lot of atoms.
>
>3. But why doesnt someone do the experiment??
*************************
April 22, 2011
I don't see the point. What is this supposed to prove? Dr. Busby's
imaginary model doesn't relate to any biologically observed phenomena.
Lifetime studies in laboratory animals fed Sr-90 from birth and other
lifetime studies of laboratory animals injected with Sr-90 have
already been performed. They do not show any increase in cancer risk
for cumulative doses below about 10 Sv. In beagles there was a
statistically significant (p<0.047) reduction in the lifetime
incidence of osteosarcoma associated with lifetime skeletal doses
less than 10 Sv.
Otto
**********************************************
Prof. Otto G. Raabe, Ph.D., CHP
Center for Health & the Environment
University of California
One Shields Avenue
Davis, CA 95616
E-Mail: ograabe at ucdavis.edu
Phone: (530) 752-7754 FAX: (530) 758-6140
***********************************************
More information about the RadSafe
mailing list