[ RadSafe ] Sv (and rems) are NOT restricted to stochastic effects?

Douglas Simpkin dsimpkin at wi.rr.com
Wed Nov 29 16:24:21 CST 2006


Ron Frick wrote:
 >ICRP 60 states: "The equivalent dose is not always the appropriate 
quantity >for use in relation to deterministic effects because the 
values of radiation >weighting factors have been chosen to reflect 
the relative biological >effectiveness (RBE) of the different types 
and energies of radiation in >producing stochastic effects.....

I've done a little digging, and while my references are a bit dated, 
what the hey, so am I.

According to Herb Attix's book on dosimetry, 1986, the 
ICRP-recommended QF for charged particles is related to the collision 
stopping power in water. This is referenced as ICRP pub no. 21, 1971, 
"Data for protection...against external sources. Supp to ICRP Pub 
15." (I do not have the update(s) to this publication to see if 
there's any newer definition.) So radiobiology, RBEs, and 
deterministic and stochastic biological effects be damned. The QF for 
heavy charged particles is defined by physics!

Additionally, Herb quotes from this same ICRP publication that the QF 
should be used "...only for routine radiation protection 
applications, and should not be used in connection with high level 
accidental exposures."

Hmmmm. So here's the fundamental question, the answer to which I 
don't know. Is  the biological effect of a high dose of alphas the 
same as that from a high dose of photons?

Eric Hall ("Radiobiology for the Radiologist" 4th ed. 1994) states 
that for another heavy charged particle "[External beams of] Protons 
have biological properties similar to x rays," this despite the fact 
that the QF for protons is 10.

I'll shut up now and leave confused.

Doug
"I thought I made a mistake once, but I was wrong."




More information about the RadSafe mailing list