[ RadSafe ] Re: Radiation Hormesis

[Steven Dapra]

Dec. 27

         Yes, don't we all love those eminent scientists.  Okay, enough on 
that front.

         ". . . proof that a substance, which had been recognized as 
carcinogenic in animals, actually causes cancer in man would require in 
most cases extemely complex and lengthy epidemiologic studies.  In many 
cases, it may be impossible to obtain such proof because of the complexity 
of controls that would be needed for a satisfactory 
demonstration.  Therefore, the only prudent course of action at the present 
state of our knowlege is to assume that chemicals which are carcinogenic in 
animals could also be so in man, although the direct demonstration in man 
is lacking."

         The citation is:  Umberto Saffiotti, "The Laboratory Approach to 
the Identification of Environmental Carcinogens," in Proceedings of the 
Ninth Canadian Cancer Research Conference 1971, edited by P. G. Scholefield 
(University of Toronto Press, 1972), pp. 23-26; cited in Federal Register 
42:192 (October 4, 1977): 54152.   I am quoting from "The Apocalyptics 
Cancer and the Big Lie," by Edith Efron (Simon and Schuster, 1984).  Efron 
quotes Saffiotti on p. 87.

         Sure, I'll grant you that was 1971 --- 36 years ago and a lot has 
changed since then.  Or has it?  Are we any closer to knowing *for certain* 
whether nor not it is possible to extrapolate from carcinogenicity in 
animals to carcinogenicity in humans?

         To further complicate matters, according to Efron, cats, dogs, 
rats, mice, and hamsters get cancer from 2-acetylaminofluorene; but guinea 
pigs, lemmings, and the cotton rat do not.  And it goes on and on.  See pp. 
198-190 of Efron for more examples of selective carcinogenicity.  She gives 
citations for everything, citing to the scientific literature, or to 
government reports on carcinogenicity.

Steven Dapra


At 09:18 PM 12/27/07 -0500, BLHamrick at aol.com wrote:
>
>And, I'm sure it comes as no surprise that anti-everythings also argue  just
>the opposite (of what Floyd noted below) about animal studies when it suits
>them.
>
>Just a couple of weeks ago (December 18, 2007), there was a very sensible
>editorial in the LA Times about the ongoing uproar regarding phthalates in
>plastics ("Stop Scaring Us").  The author was roundly attacked in 
>three  letters
>(published December 23, 2007).  (One from the eminent scientist  Senator 
>Diane
>Feinstein - said with tongue firmly in cheek).  And, of  course, one of the
>criticisms was that the columnist had dared to suggest that  because 
>phthalates
>cause cancer in rats, it doesn't necessarily mean it will  cause it in humans.
>
>The letter to the editor stated, "[The columnist] repeats the old saw that
>rats have different metabolism than people. So he'd rather test people? 
>Animal
>testing to predict risks posed to humans by toxic substances is a
>well-established principle that provides the basis for the nation's 
>fundamental  cancer
>policy and a host of laws seeking to protect us against this deadly  disease.
>If a chemical can induce tumors in mice, we are not immune."
>
>The problem I have with the anti-everythings (aside from the  cherry-picking)
>is they seem to be quite willing to make any argument, even  to the point
>where they may make two completely inconsistent arguments depending  on 
>the day
>of the week (or the audience), to support their agenda.
>
>Barbara L. Hamrick
>
>In a message dated 12/27/2007 11:10:49 AM Pacific Standard Time,
>Floyd.Flanigan at nmcco.com writes:
>
>I am a  firm supporter of Hormesis but with all of the other
>environmental  influences which can mask most true expressions of the
>Hormetic Effect, I  fear it will be a very long time before we see such a
>study. I suppose it  could be conducted on lab animals, but no matter
>what evidence was  produced, the nay-sayers would find their way back to
>the fact that humans  have a different physiology than the test  subjects.
>