Re: Question on low-dose rad effects

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

	An extension of the question asked here is why does a 25 gram
mouse have the same risk as a 100,000 gram person for a given energy
deposit per gram? I would bet that elephants also have similar risk.

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 Thu, 21 Oct 1999, Jerry Cohen wrote:

> Dear Radsafers,
>      Perhaps someone could enlighten me on something that has puzzled me for
> a long time. Why is the degree of harm, detriment, etc. from low-level
> radiation  expressed in terms of rad, rem, sieverts, etc. which are
> functions of absorbed energy per unit mass (i.e. ergs/gm)?
>  Isn't the probability of a mutation, or other adverse effect a direct
> function of the total number of ionizing events occuring in the vicinity of
> suseptible DNA molecules and isn't that ,in turn, a function only of total
> absorbed energy?
>      For example, consider two individuals of the same age, sex, and general
> state of health with the only difference between the two being that one
> weighs twice as much as the other.  Given that both recieve a radiation dose
> of say 1.0 rem, have they both experienced an equal degree of harm? Due to
> his/her larger mass, the heavier individual gets twice as many ionizing
> events occuring near twice as many DNA molecules any one of which might
> result in an adverse mutation.  Why doesn't the individual with twice the
> mass, get twice the risk???     Jerry Cohen
> jjcohen@prodigy.net
> 
> 
> 
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