[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
RE: [Fwd: Chernobyl Study Reveals First Direct Evidence]
Folks,
Maybe I missed something in earlier messages, but my reaction to the recent
post concerning increased child thyroid CA incidence in the Chernobyl child
cohort was "ok, so tell me something else obvious". There are published
data as far back as 1996 that clearly shows a 50-200-fold increase in child
thyroid CA incidence, depending on the specific sub-population examined. If
one looks at the Gomel oblast of Belarus, the most highly contaminated area,
the child thyroid CA is ~200 times the pre-accident incidence. The exact
increase is arguable because of the uncertainty in pre-1986 data, but the
post-1986 trend is absolutely obvious.
While I have no first-hand data, I believe (opinion based on first-hand
observation while in Ukraine) that a major factor in this increased
incidence is the result of an iodine-deficient diet in the local population.
This would result in a higher uptake fraction, substantially affecting the
dose-per-unit-intake.
George J. Vargo, Ph.D., CHP
Senior Scientist
MJW Corporation
http://www.mjwcorp.com
610-925-3377
610-925-5545 (fax)
vargo@physicist.net
-----Original Message-----
From: owner-radsafe@list.vanderbilt.edu
[mailto:owner-radsafe@list.vanderbilt.edu] On Behalf Of Dr. Peter Hill
Sent: Monday, September 13, 2004 9:38 AM
To: radsafe@list.vanderbilt.edu
Cc: jacob@gsf.de
Subject: Re: [Fwd: Chernobyl Study Reveals First Direct Evidence]
Dear collegues,
below You find the response of a non-listmember to a recent mailing on
this list (article in Sandy's news distribution). P.Jacob is one of the
leading scientists in this field and well known for his pioneering work.
Those in the field know the references given, for others it might still make
exciting reading. Any responses might be directed not to me , but directly
to him (mailto:jacob@gsf.de).
Greetings
P.Hill
------------
TO WHOM IT MAY CONCERN
The first part of the title of the text below is quite surprising. The
association between the exposure of the thyroid due to I-131 released by
theChernpbyl accident has already been shown and quantified in studies that
were performed several years before the study mentioned. Relevant references
are:
P. Jacob, G. Goulko, W. Heidenreich, I. Likhtarev, I. Kairo, N.D. Tronko,
T.I. Bogdanova, J. Kenigsberg, E. Buglova, V. Drozdovitch, A. Goloneva, E.P.
Demidchik, M. Balonov, I. Zvonova, V. Beral: Radioactive iodine risk to
children estimated. Nature 392, 31-32 (1998)
P. Jacob, J. Kenigsberg, I. Zvonova, W.F. Heidenreich, E. Buglova, G.
Goulko, V. Drozdovovitch, A. Golovneva, E.P. Demidchik, M. Balonov, H.G.
Paretzke: Chernobyl exposure during childhood and thyroid cancer incidence
in Belarus and Russia. Brit. J. Cancer 80, 1461-1469 (1999)
Peter Jacob
--
ATTENTION
My mails are selected by a spam filter.
Occasionally it may happen that an incoming mail is directed by mistake into
the junk folder. If you want to be sure that I read your e-mail, please
request a cofirmation that the mail has been opened.
Dr. Peter Jacob
GSF National Research Center
Institute of Radiation Protection
D-85764 Neuherberg
Germany
Tel: +49 (0)89 3187 4008
Fax: +49 (0)89 3187 3363
<http://www.gsf.de/ISS/deutsch/risiko/inhalt4.phtml>http://www.gsf.de/ISS/de
utsch/risiko/inhalt4.phtml
........
>>Date: Thu, 02 Sep 2004 12:17:42 -0700
>>From: Sandy Perle <mailto:sandyfl@earthlink.net><sandyfl@earthlink.net>
>>Subject: Chernobyl Study Reveals First Direct Evidence
>>........
>>
>>Chernobyl Study Reveals First Direct Evidence That Risk of Thyroid
>>Cancer Rises With Increasing Radiation Dose
>>
>>SEATTLE, Sept. 1 /PRNewswire/ -- The risk of thyroid cancer rises with
>>increasing radiation dose, according to the most thorough risk analysis
for thyroid cancer to date among people who grew up in the shadow of the
1986 Chernobyl power-plant disaster.
>>
>>The incidence of thyroid cancer was 45 times greater among those who
>>received the highest radiation dose as compared to those in the
lowest-dose group, according to a team of American and Russian researchers
led by Scott Davis, Ph.D., and colleagues at Fred Hutchinson Cancer Research
Center. They report their findings in the September issue of Radiation
Research.
>>
>>"This is the first study of its kind to establish a dose-response
>>relationship between radiation dose from Chernobyl and thyroid cancer,"
said Davis, referring to the observation that as radiation doses increase,
so does the risk of thyroid cancer. "We found a significant increased risk
of thyroid cancer among people exposed as children to radiation from
Chernobyl, and that the risk increased as a function of radiation dose."
>>
>>Having such information in hand, Davis said, may help officials better
>>predict what long-term health effects to expect in the event of a similar
nuclear accident or terrorist attack.
>>
>>"Another potential benefit of the findings is that it allows officials
>>to more accurately understand and document the magnitude of the
thyroid-cancer burden that has resulted from Chernobyl. This information
will be important in designing and maintaining programs targeted toward the
victims of the disaster."
>>
>>While about 30 people were killed immediately from the blast, which
>>remains the worst accident of its kind in history, an estimated 5 million
people were exposed to the resulting radiation.
>>
>>"Prior to Chernobyl, thyroid cancer in children was practically
>>nonexistent. Today we see dozens and dozens of cases a year in the regions
contaminated by the disaster, and the incidence continues to rise," Davis
said. "This provides some evidence that there's an excess of thyroid cancer
in children and in people who were children at the time of the accident.
However until now nobody had taken the next step to find out just how much a
risk there is and whether it rises along with radiation dose."
>>
>>While previous Chernobyl studies have relied on broad-stroke estimates
>>of radiation exposure based on such factors as ground contamination,
geographic proximity to the northern Ukraine plant or other surrogate
measures of exposure, this study is the first of its kind to factor into the
equation individualized estimates of radiation dose based on in-person
interviews about diet and other lifestyle factors, said Davis, a member of
Fred Hutchinson's Public Health Sciences Division.
>>
>>"After all these years, many efforts have been made by various
>>research groups around the world to study the health effects of Chernobyl,
and hundreds of scientific papers have been published. But ours is the first
report that provides quantitative estimates of thyroid-cancer risk in
relation to individual estimates of radiation dose," said Davis, also
chairman of the Department of Epidemiology at the University of Washington
School of Public Health and Community Medicine in Seattle.
>>
>>Kenneth Kopecky, Ph.D., a biostatistician in Fred Hutchinson's Public
>>Health Sciences Division, was the study's co-investigator and directed the
data analysis. Public Health Sciences Division staff managed and coordinated
all aspects of the project. They included Theresa Taggart (project manager),
Lynn Onstad (statistician), Teri Kopp (administration) and Laurie Shields
(research coordinator).
>>
>>The Fred Hutchinson team organized a collaborative effort with a dozen
>>scientists at four Russian institutions to conduct this research: the
Medical Radiological Research Center (in Obninsk), the Byransk Diagnostic
Center and the Bryansk Institute of Pathology (both in Bryansk), and the
National Center of Hematology (in Moscow). All investigators were members of
the International Consortium for Research on the Health Effects of Radiation
funded by the U.S. Office of Naval Research.
>>
>>The researchers focused their efforts on western part of the Bryansk
>>Oblast of Russia. This region, located about 66 miles northeast of
Chernobyl, is the most heavily contaminated area in the Russian Federation.
This was the first study of this type among residents of the Russian
Federation exposed to Chernobyl radiation.
>>
>>Working through a local cancer registry, the researchers identified 26
>>people with thyroid cancer who were less than 20 years old when the
Chernobyl accident occurred; the majority were under 16 when their thyroid
cancers were diagnosed. They then identified 52 healthy control subjects
from the general population for comparison purposes. The controls and cancer
cases were matched by age and place of residence at the time of the
accident.
>>
>>The researchers then set about collecting information from these
>>individuals and their mothers or fathers that would allow them to estimate
each person's radiation dose using computer models. Interviews took place in
the home and were conducted by Russian physicians.
>>
>>Individual doses depended largely on the ingestion patterns of food
>>contaminated with radioactive iodine-131 (I-131), which concentrates in
the thyroid gland. The primary source of food-based I-131 was milk from cows
that grazed on contaminated pastures. Radiation doses to the thyroid
increased along with the amount of milk and dairy products consumed.
External, airborne radiation and contamination of other foods also
contributed somewhat to the overall dose, depending on the person's
proximity to the plant at the time of the accident. These doses were all
received within the first few months after the accident, before the I-131 in
the environment decayed into non-
>>radioactive elements. While other radioactive contaminants remain in the
area, they do not cause appreciable doses of radiation to the thyroid.
>>
>>In addition to the study's ability to estimate individual radiation
>>doses based on personal interviews, other strengths of the study included
the fact that all cases of thyroid cancer were confirmed independently by a
panel of expert pathologists, and the study focused on people exposed as
young children and adolescents, a group that is likely to be most
susceptible to the effects of radiation exposure to the thyroid gland.
Limitations of the study included its small sample size and its reliance on
individual recall for reporting factors such as milk-consumption patterns
that were used to estimate radiation dose.
>>
>>Efforts are under way to investigate a larger population in a similar
>>fashion to see if these findings can be replicated, Davis said.
>>
>>For his contributions to the field, earlier this year Davis became the
>>first foreign epidemiologist elected to the Russian Academy of Medical
Sciences. The group's status in that country is on a par with the esteemed
National Academy of Sciences in the United States. In May he received an
honorary diploma in Moscow.
>>
>>Davis and colleagues have extended their cancer-risk studies to older
>>Chernobyl survivors and are investigating how the damage caused to DNA by
radiation influences the risk of developing thyroid cancer.
>>
>>This work is part of Fred Hutchinson's Global Health Initiative, which
>>focuses on international collaboration to understand and solve some of the
most widespread health problems in the world, including cancer and
infectious diseases.
>>
>>Providing some long-awaited answers to Chernobyl survivors has been a
>>rewarding research endeavor for Scott Davis, Ph.D., and colleagues at Fred
Hutchinson Cancer Research Center, but it hasn't been a straightforward one.
>>
>>Some of the team's greatest achievements were simply establishing the
>>working relationships and infrastructure to get the studies off the
ground.
>>
>>"Within the first year of the 1986 accident, we were very interested
>>in seeing if we could get involved and participate in long-term studies of
health effects," Davis said. "But at the time of the accident, our
government and that of the former Soviet Union were not so friendly, so
establishing connections through that route didn't work."
>>
>>But in 1990, an opportunity surfaced when a Russian helicopter pilot
>>involved in the initial efforts to contain the Chernobyl radiation
developed leukemia and came to Fred Hutchinson for a bone-marrow transplant.
After his treatment, an informal exchange program began between Fred
Hutchinson and the National Center for Hematology in Moscow, whose director
approached the center for assistance in developing a research and treatment
institute for victims of the accident. Davis and colleague Kenneth Kopecky,
Ph.D., made their first trip to Moscow that year.
>>
>>Then, in 1992, the Soviet Union collapsed. "We were back to square one
>>in terms of negotiations," Davis said.
>>
>>But, thanks to efforts by Fred Hutchinson's then-president and
>>director, Robert W. Day, M.D., and by the late Adm. Elmo Zumwalt, a former
center trustee and former chief of naval operations for the U.S. Navy, new
relationships were established. In 1992, a research consortium consisting of
three international teams working in Russia, Belarus and Ukraine was created
to study long-term health effects of the radiation released at Chernobyl.
>>
>>"Our initial work in Russia was simply to conduct small pilot studies
>>to establish in concrete terms whether we could carry out all phases of an
epidemiological study," Davis said. "There was no history of doing this kind
of research in Russia or the other two countries. We had to set it all up
from scratch."
>>
>>Challenges included purchasing Russian vehicles for the field teams
>>using federal dollars -- an unprecedented bureaucratic challenge for the
researchers -- importing all laboratory equipment and supplies, and then
figuring out a way to maintain them without the standard resources that one
takes for granted in the United States.
>>
>>"It's been a long haul and an enormous amount of time and work," Davis
>>said, whose 30-plus trips to the former Soviet Union include walking the
grounds of the evacuated plant and surveying the desolated 30-kilometer
evacuation zone.
>>
>>Once the team established the capability to do the research, the group
>>began its studies of thyroid cancer, a disease linked to radiation
exposure. By the early 1990s, many new cases of the disease, particularly
among young children, were diagnosed in regions near the blast. Since then,
reports show several hundred cases of thyroid cancer in young children in
the three countries contaminated by Chernobyl, a trend that appears to be
continuing.
>>
>>Despite the lack of resources available to initiate these studies,
>>Davis said that scientists and citizens of the three countries were eager
for the research from the start. "Our collaborators in Russia have been
terrific colleagues," he said. "We now have very close ties with our partner
institutions."
>>
>>He also credited the strong encouragement and support from Fred
>>Hutchinson's senior administration for helping him establish stable
working relationships with their overseas colleagues.
>>
>>"The incredible support and flexibility of the center, especially in
>>the early stages, really made this happen. That can't be overstated,"
Davis said.
>>------------------
............................
============================
Dr. Peter Hill
Forschungszentrum Jülich GmbH
S-B
52425 Jülich
Germany
++49-2461-615081
++49-2461-612166 (FAX)
mailto:p.hill@fz-juelich.de
************************************************************************
You are currently subscribed to the Radsafe mailing list. To unsubscribe,
send an e-mail to Majordomo@list.vanderbilt.edu Put the text "unsubscribe
radsafe" (no quote marks) in the body of the e-mail, with no subject line.
You can view the Radsafe archives at http://www.vanderbilt.edu/radsafe/
************************************************************************
You are currently subscribed to the Radsafe mailing list. To
unsubscribe, send an e-mail to Majordomo@list.vanderbilt.edu Put the
text "unsubscribe radsafe" (no quote marks) in the body of the e-mail,
with no subject line. You can view the Radsafe archives at
http://www.vanderbilt.edu/radsafe/