[ RadSafe ] FW: Re: Radiation risk paper by S-L Hwang et al.

[HOWARD.LONG at comcast.net]

 "Scott, Bobby" <BScott at lrri.org>, "Kazuo SAKAI" <kazsakai at nirs.go.jp>, "Dr Kaushala Prasad Mishra" <mishra_kaushala at rediffmail.com>, <bnp at barc.gov.in>, "Carmel Mothersill" <mothers at mcmaster.ca>, "Jaworowski, Zbigniew" <jaworo at clor.waw.pl>, "Jane Orient" <jorient at mindspring.com>, <stoneh at mail.nih.gov>, "Hirsch, Roland" <Roland.Hirsch at science.doe.gov>, "Cyndi Jones" <CGJ at nrc.gov>, <edouple at nas.edu>, "Mikhail, Isis (NIH/NCI) [E]" <mikhaili at mail.nih.gov>, "Ludwig E. Feinendegen" <feinendegen at gmx.net>, "Jerry Cuttler" <jerrycuttler at rogers.com>, <howard.long at comcast.net>, "Sykes, Pamela (FMC)" <Pamela.Sykes at fmc.sa.gov.au>, "Edouard Azzam" <azzamei at umdnj.edu>, "Mitchel, Ron" <mitchelr at aecl.ca>, <kooyoomjian.jack at epamail.epa.gov>, "Kozumbo, Walter J Civ AFRL/AFOSR" <walter.kozumbo at afosr.af.mil>, <hsducoff at uiuc.edu>, <boreham at mcmaster.ca>, "Brenda Laster" <blaster at bgu.ac.il>, <krithidech at notes.cc.sunysb.edu>, "Galina V. Zhuntova" <clinic at ozersk.com>, "Cohen, Bernie" <BLC+ at pitt.edu>, drlius
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Subject: Re: Radiation risk paper by S-L Hwang et al. 
Date: Wed, 6 Aug 2008 16:35:10 +0000 

Radsafe,
Selection of data (using a model that hides the hormesis of low dose radiation) is not only unscientific but dishonest. Bobby Scott describes below how this was done here: "2 years of dose was thrown away for leukemia and 10 years of dose was thrown away for solid cancers." 

Like the removal of data (from the 1000 AD good warm period) to invent the notorious "hockey stick" and scare up global warming carbon tax money, or like the one-tailed test used to hide the benefit to nuclear shipyard workers   (before Cameron exposed the fraud), such political distortion must be challenged by all honest scientists - even if it threatens their future funding by the state. I detail similar fraud by the Women's Health Initiative (NIH and Universities) in my letter in the current Journal of American Physicians and Surgeons, "Government-Education Complex Hides Risk".

"Who pays the piper calls the tune". Radiation benefit is again being denied the public by socialist-"environmentalist" politicians. Private research is less distorted than socialized research.

Howard Long MD MPH

-------------- Original message -------------- 
From: "Scott, Bobby" <BScott at lrri.org> 

Dear Colleagues:
 
Attached is a new paper by S-L Hwang et al. entitled “Estimates of relative risk for cancers in a population after prolonged low-dose-rate radiation exposure: A follow-up assessment from 1983 to 2005” that was published in Radiation Research 170:143-148, 2008. I thought you may find the paper to be of interest given that it relates to cancer occurrence among Taiwanese residents that received protracted gamma irradiation over a number of years. Earlier studies by others related to this population demonstrated a very large protedctive effect (adaptive response) of the low-rate gamma irradiation but such finding are now too often discounted on the basis that they “fly in the face of the BEIR VII Report” which essentially supposedly validated the LNT model. The BEIR committees that prepare the BEIR reports rely on papers such as the attached in justifying continued use o f the LNT model.  Some of my comments related to the paper follow in case they may be of interest.
 
The researchers used a nonlinear model in which the hazard ratio (an estimate of relative risk) increased exponentially with radiation dose according to the function exp[b3X3] where X3 is the truncated radiation dose divided by 100 mGy (i.e., truncated dose in units of 100 mGy).  Thus, X3 = 1 corresponds to a truncated dose of 100 mGy. 
 
In truncating the dose, 2 years of dose was thrown away for leukemia and 10 years of dose was thrown away for solid cancers. This practice is common in many epidemiological studies but cannot be justified based on current knowledge of radiation biology (e.g., high dose suppression of immunity against cancer).  For example, one should not throw away dose that suppresses immunity allowing for cancers to occur that would otherwise have not occurred during the period of observation.
 
With the indicated model, value of b3 > 1 would imply a rising nonlinear, threshold-type (effective threshold), dose-response curve that would have a slope that increases progressively as dose increases (i.e., non-LNT-type curve).  b3 = 2 would be a pure quadratic dose-response. Similarly, b3 = 3 would be a cubic dose-response.
 
Values of b3 < 1 (but  not negative or zero) would imply a rising nonlinear dose-response curve also, but one who’s slope progressively decreases as dose increases (negative curvature) and one for which there was no threshold.  Thus, the researchers have used nonlinear dose-response functions for the different endpoints evaluated. 
 
Interestingly, the authors didn’t report the values they obtained for b3 nor did they report the actual data they used for hazard ratios.  I suspect that b3 probably differed f or each dose-response curve studied and was negative in some cases (e.g., for thyroid and rectal caner). A negative value is required in order to get a hazard ratio < 1 (adaptive response) as was reported for thyroid and rectal cancers [see Table 2]. 
 
There appears to be no unexposed group (i.e., natural background radiation only).  The lowest dose group appears to have also been exposed to gamma rays.  Thus, their study design has very little power for detecting an adaptive response (except when very large as may have been the case for rectal cancer). For rectal cancer, the lower 90% CI for the hazard ratio at 100 mGy (truncated dose) is 0.02 (compared to the no effect value of 1). 
 
Even with the seriously flawed study design they used, they were not able to show an increase in risk for (1) all cancers, (2) all cancers excluding leukemia, and (3) all solid cancers. Interesting, this was not mentioned in the abstract which states “The results further strengthen the association between protracted low-dose radiation and cancer risks…”
 
I am very surprised that Radiation Research would publish such a paper. Any comment you may have on the paper would be welcomed.
 
Best wishes,
Bobby R. Scott, Ph.D.
Senior Scientist
Lovelace Respiratory Research Institute
2425 Ridgecrest Drive SE
Albuquerque, NM 87108
Phone: 505-348-9470