[ RadSafe ] Natural gamma rays supposedly linked tochildhood leukemia

Tue Jul 10 03:00:08 CDT 2012

Dear Bobby  Let me just point to the Kerala paper on spontaneous DNA damage
vs background:  Kumar et al. Radiat. Res. 177: 643-650 (2012).  -  By the
way, the reassessment of the atom bomb survivor cancer incidence ERR - Ozawa
et al Radiat Res 177:229-243 (2012) - clearly shows no cancer increase at
doses below ~ 100 mGy.  All the best, Ludwig

-----Ursprüngliche Nachricht-----
Von: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] Im Auftrag von Scott, Bobby
Gesendet: Sonntag, 1. Juli 2012 23:36
An: The International Radiation Protection (Health Physics) MailingList; The
International Radiation Protection (Health Physics) Mailing List
Betreff: Re: [ RadSafe ] Natural gamma rays supposedly linked tochildhood
leukemia

Socio-economic status was also considered. Cumulative radiation equivalent
dose to bone marrow was used as an independent variable. Cumulative
radiation equivalent dose (or absorbed dose) as an independent variable can
be problematic for studies of possible effects of exposure of children to
natural background radiation since any stochastic biological effect (e.g.,
cancer) that evolves over time after birth would be expected to correlate
with time living as a child, irrespective of the actual cause of the
biological effect (e.g., something other than radiation). The cumulative
radiation dose from natural radiation increases as the time living
increases. Thus, case-control-study findings such as indicated by Kendall et
al. may simply be reflecting a correlation between cumulative radiation dose
and time living as a child.

Bobby
B.R. Scott

________________________________

From: Ludwig E. Feinendegen [mailto:feinendegen at gmx.net]
Sent: Fri 6/29/2012 2:55 AM
To: 'The International Radiation Protection (Health Physics) Mailing List'
Subject: Re: [ RadSafe ] Natural gamma rays supposedly linked tochildhood
leukemia

Thank you, Bobby.  You have led the authors ad absurdum!  I believe, that
the paper would not have been accepted for print if it would not serve the
radiation phobia universe. Does Kendall's paper also suffer from a lack of
paying attention to confounding factors that may differ regionally?  Was the
background radiation level the only variable in their regional analyses?
Unfortunately, I have not been able to get the full paper.  Best, Ludwig

-----Ursprüngliche Nachricht-----
Von: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] Im Auftrag von Scott, Bobby
Gesendet: Donnerstag, 28. Juni 2012 23:21
An: radsafe at health.phys.iit.edu
Cc: Dan McCarn; Brennan, Mike (DOH); Andy Howard; Dixon, John E.
(CDC/ONDIEH/NCEH)
Betreff: [ RadSafe ] Natural gamma rays supposedly linked to childhood
leukemia

Hi All,

I have taken a look at the new paper by G. M. Kendall et al. in the Leukemia
Journal claiming a link between natural background gamma rays and childhood
leukemia. The paper is titled "A record-based case-control study of natural
background radiation and the incidence of childhood leukaemia [leukemia] and
other cancers in Great Britain during 1980-2006." Because of the additional
radiation-phobia-related casualties in Japan that could be promoted by this
article, I thought it to be important to take a close look at the modeling
approach used by the researchers.  Of special interest was the mathematical
form used for relative risk (RR) evaluation and what values of RR would be
expected based on the RR function used when radiation doses are
significantly greater than those from natural background.  The authors used
an exponential form for relative risk , i.e., RR = exp(alpha*dose) for the
natural background radiation effect. The authors claim that their calculated
12% excess relative risk (ERR) of childhood leukemia per mGy of cumulative
red-bone-marrow dose from natural-background-related gamma rays supports the
extrapolation of high-dose-rate risk models (e.g., based on A-bomb
survivors) to low-rate exposure.  A 12% excess relative risk per mGy after
low-dose, low-rate exposure implies a value of 0.12 per mGy for the
parameter alpha.  With this value, RR for childhood leukemia at 100 mGy
(similar to the annual dose from natural background radiation for the Kerala
coast, India) would be calculated to be RR =
exp(12) = 162,755. For a 200 mGy (20 rad) dose (similar to the annual dose
from natural background radiation in Ramsar, Iran), RR would be calculated
to be 26,489,122,130. As I think others may agree, such a derived
dose-response function for leukemia RR for children raises serious questions
about the validity of the results of the study of Kendall et al.

Best wishes,

Bobby

B. R. Scott

Lovelace Respiratory Research Institute

2425 Ridgecrest Drive SE

Albuquerque, NM 87108, USA

****************************************************************************
***

This e-mail and any files are protected by the Electronic Communications
Privacy Act, 18 U.S.C. Sections 2510-2521. Its intended to be delivered only
to the named
addressee(s) and its content is confidential and privileged. If you are not
the intended recipient or the person responsible for delivering the e-mail
to the intended recipient, be advised that you have received this e-mail in
error and that any use, dissemination, forwarding, printing, or copying of
this e-mail is prohibited. If you have received this e-mail in error, please
notify the sender by replying to this message and delete this e-mail
immediately. Nothing in this communication, either written or implied,
constitutes or should be construed as a legally binding agreement between
the parties with respect to the subject matter herein.
_______________________________________________
You are currently subscribed to the RadSafe mailing list

Before posting a message to RadSafe be sure to have read and understood the
RadSafe rules. These can be found at:
http://health.phys.iit.edu/radsaferules.html

For information on how to subscribe or unsubscribe and other settings visit:
http://health.phys.iit.edu <http://health.phys.iit.edu/> 

****************************************************************************
***

This e-mail and any files are protected by the Electronic Communications
Privacy Act, 18 U.S.C. Sections 2510-2521. Its intended to be delivered only
to the named
addressee(s) and its content is confidential and privileged. If you are not
the intended recipient or the person responsible for delivering the e-mail
to the intended recipient, be advised that you have received this e-mail in
error and that any use, dissemination, forwarding, printing, or copying of
this e-mail is prohibited. If you have received this e-mail in error, please
notify the sender by replying to this message and delete this e-mail
immediately. Nothing in this communication, either written or implied,
constitutes or should be construed as a legally binding agreement between
the parties with respect to the subject matter herein.
_______________________________________________
You are currently subscribed to the RadSafe mailing list

Before posting a message to RadSafe be sure to have read and understood the
RadSafe rules. These can be found at:
http://health.phys.iit.edu/radsaferules.html

For information on how to subscribe or unsubscribe and other settings visit:
http://health.phys.iit.edu