Exposure to low levels of ionizing radiation

[Randy Walsh]

(repost - Original author Bill Nichols)

Welcome Rad Workers, HP / RP's and visitors,

(To the employees of CPNPP, this thread is aimed at a larger audience than just CPNPP)

Exposure to low levels of ionizing radiation is far more harmful than is widely believed.

Did you wonder why CPNPP reduced its annual dose limit to 2 REM? Because
all of the international bodies (NCRP, ICRP, BEIR, UNSCEAR, IAEA and even
the NRC) have said so. Why hasn't this been published? Well, the
ramifications are astounding.
UNSCEAR has published that the annual dose limit should be 1 REM. In one
of its lengthy white papers, the NRC agreed except that it would cost too
much to implement!

The reason that all of the agencies are reducing their suggested annual
dose limit is a direct result of research that has proven that low doses
are harmful.
Next, in January of 2005 the CDC added to its list of KNOWN carcinogens,
X-rays of less than 300 KeV. Since that time, they've removed the energy
threshold and have included alphas, neutrons and gammas.
BEIR V was published in 1990. We're currently working under BEIR VII and
are moving to BEIR VIII. Why? Because the body of evidence continues to
mount that low doses, the kind to which we are exposed, has been found to
cause cancer at a rate greater than was originally thought.
Contrary to what each of us was told in our respective Nuclear 101
courses, research has revealed that dose received by older people, while
identical in effect with younger folks, does more damage. The logic is
really quite simple (why didn't it occur to us?): older people don't have
the same recuperative ability as younger people.
Here's the most sobering detail of all the research: cancers become
prevalent at life-time exposures of 10 REM. Guess what; I'm at 17 REM.

Have you asked yourself why we are paying such close attention to
fractions of an mR? Have you wondered, too, why we budget Sooooooooooooo
closely, our individual, department and station dose? Again, the answer
is simple: because we've been directed by the international agencies to
account for every single mR.

Now; here's what I propose we do with this information: insist on free,
lifetime health care for our members. The analogy to the asbestos
industry is unmistakable. There was a time when the asbestos industry was
"safe" and then it wasn't. We work in a cancer factory (it doesn't really
matter if you believe that or not) and it's only right and fitting that
our employer should provide the necessary health care to treat our
collective cancers.

I'll include a couple of links so that you don't think I'm too whacked.
For your own enjoyment, google: effects of low level exposure to ionizing
radiation; I think you'll be surprised.

[ballscratcher(bnichols)]

How about this one (there's a link to the original paper at the top of the article)?

www.ncbi.nlm.nih.gov/pubmed/10069248?dopt=Abstract

Age at exposure modifies the effects of low-level ionizing radiation on cancer mortality in an occupational cohort.

Ritz B, Morgenstern H, Moncau J.

Department of Epidemiology and Center for Occupational and Environmental Health, School of Public Health, University of California, Los Angeles 90095-1772, USA.

In a cohort of 4,563 nuclear workers followed retrospectively from 1950 to 1994, we found that age at exposure modified the effects of external radiation dose on cancer mortality. Analyses involved application of conditional logistic regression to risk sets of age- and calendar time-matched cancer deaths, with covariates treated as time dependent and with cumulative radiation doses divided according to the age intervals in which exposure occurred. After adjustment for confounding factors, we found that workers exposed to external radiation after the age of 50 years experienced exposure-related elevations in mortality from cancer at any site [rate ratio (RR) = 1.98; 95% confidence interval (CI) = 0.63-6.26], radiosensitive solid cancer (RR = 3.29; 95% CI = 1.10-9.89), and lung cancer (RR = 3.89; 95% CI = 1.23-12.3) substantially greater (1.6- to 3.5-fold greater) than were seen in coworkers exposed at all earlier ages. In contrast, all of the radiation doses contributing to mortality from cancers of the blood and lymph system were received before age 50 (for age <50, RR = 2.73 and 95% CI = 1.46-5.10; for age > or =50, RR = 0.24 and 95% CI = 0.00-687). Our results for cancer of any site are consistent with the results of previous studies examining the effects of exposure age in nuclear workers. Thus, effects of low-level radiation doses may depend on exposure age, and furthermore, patterns of effect modification by age may differ by type of cancer.

[ballscratcher(bnichols)]

(The link to this one is at the bottom of the page) This paper establishes that X-rays and gamma rays are known carcinogens (they were added to the Centers for Disease Control list of known carcinogens in 2005).

National Toxicology Program, Department of Health and Human Services

SUBSTANCE PROFILES
Ionizing Radiation
Introduction
Radiation that has sufficient energy to remove electrons from atoms is called “ionizing radiation.” Ionization results in the production of negatively charged free electrons and positively charged ionized atoms. Ionizing radiation can be classified into two groups: photons (includes X-radiation and gamma radiation) and particles (includes alpha and
beta particles and neutrons). The radioactive compound thorium dioxide, which decays by emission of alpha particles, was first listed in the Second Annual Report on Carcinogens (1981), and radon and its most common isotopic forms (radon-220 and radon-222), which also emit primarily alpha particles, were first listed in the Seventh Annual Report on Carcinogens (1994). Three types of ionizing radiation (X-radiation, gamma radiation, and neutrons) were first listed in the Eleventh Report on Carcinogens (2004). X-radiation and gamma radiation are included in one listing. The profiles for X-radiation and gamma radiation, neutrons, radon, and thorium dioxide, which are listed as known to be human carcinogens, follow this introduction.

X-Radiation and Gamma Radiation*
Known to be Human Carcinogens
First Listed in the Eleventh Report on Carcinogens (2004)

Carcinogenicity
X-radiation and gamma radiation are known to be human carcinogens based on sufficient evidence in humans. Epidemiological studies of radiation exposure provide a consistent body of evidence for the carcinogenicity of X-radiation and gamma radiation in humans. Exposure to X-radiation and gamma radiation is most strongly
associated with leukemia and cancer of the thyroid, breast, and lung; associations have been reported at absorbed doses of less than 0.2 Gy (see “Properties,” below, for explanation of radiation dose measurement). The risk of developing these cancers, however, depends to some extent on age at exposure. Childhood exposure is mainly
responsible for increased leukemia and thyroid-cancer risks, and reproductive-age exposure for increased breast-cancer risk. In addition, some evidence suggests that lung-cancer risk may be most strongly related to exposure later in life. Associations between radiation exposure and cancer of the salivary glands, stomach, colon, bladder, ovary, central nervous system, and skin also have been reported, usually at higher doses of radiation (1 Gy) (Kleinerman et al. 1995, Ron 1998, Ron et al. 1999, Brenner et al. 2000, Garwicz et al. 2000, Lichter et al. 2000, Sont
et al. 2001, Yeh et al. 2001, Bhatia et al. 2002). The first large study of sarcomas (using the U.S. Surveillance,
Epidemiology, and End Results cancer registry) (Yap et al. 2002) added angiosarcomas to the list of radiation-induced cancers occurring within the field of radiation at high therapeutic doses. Two studies, one of workers at a Russian nuclear bomb and fuel reprocessing plant (Gilbert et al. 2000) and another of Japanese atomic-bomb survivors (Cologne et al. 1999), suggested that radiation exposure could cause liver cancer at doses above 100 mSv (in the worker population especially with concurrent exposure to radionuclides). Among the atomic-bomb survivors, the liver-cancer risk increased linearly with increasing radiation dose. A study of children medically exposed to radiation (other than for cancer treatment) provided some evidence that radiation exposure during childhood may increase the incidence of lymphomas and melanomas. In addition, chronic lymphatic leukemia, Hodgkin’s disease (malignant lymphoma), and cancer of the cervix, prostate, testis, and pancreas are generally considered not to be associated with radiation exposure.
X-radiation and gamma radiation are clearly carcinogenic in all species of experimental animals tested (mouse, rat, and monkey for Xradiation and mouse, rat, rabbit, and dog for gamma radiation). Among these species, radiation-induced tumors have been observed in about 17 tissues or organs, including those observed in humans (i.e.,
leukemia, thyroid gland, breast, and lung) (IARC 2000). Susceptibility to induction of benign and malignant tumors depends on tissue site, species, strain, age, and sex. Early prenatal exposure does not appear to cause cancer, but exposure at later stages of prenatal development has been reported do so. It has been suggested that radiation exposure of mice before mating increases the susceptibility of their offspring to cancer, but study results are conflicting.

Additional Information Relevant to Carcinogenicity
X-radiation and gamma radiation have been shown to induce a broad spectrum of genetic effects, including gene mutations, minisatellite mutations (changes in numbers of tandem repeats of DNA sequences), micronucleus formation (a sign of chromosome damage or loss), chromosomal aberrations (changes in chromosome structure or number), ploidy changes (changes in the number of sets of chromosomes), DNA strand breaks, and chromosomal instability. Genetic damage by Xradiation or gamma radiation has been observed in humans exposed accidentally, occupationally, or environmentally, in experimental animals exposed in vivo, and in cultured human and other mammalian cells. Xradiation and gamma radiation induce genetic damage in somatic cells and transmissible mutations in mammalian germ cells (sperm and egg cells and their precursors). The DNA molecule may be damaged directly, by interaction with ionizing radiation, or indirectly, by interaction with reactive products of the degradation of water by ionizing radiation (i.e., free electrons, hydrogen free radicals, or hydroxyl radicals) (IARC 2000, NTP 2003). The observed genetic damage is primarily the result of errors in DNA repair, but may also arise from errors in replication of damaged DNA. Epigenetic mechanisms (factors other than the primary DNA sequence) that alter the action of genes also may be involved in radiation-induced carcinogenesis. Proposed mechanisms for delayed or
indirect radiation-induced genetic damage include genomic instability, induction of mutations by irradiation of the cytoplasm of the cell, and “bystander effects,” in which genetic damage is induced in cells that were not directly exposed to ionizing radiation, apparently through cell signaling pathways.
Properties
As forms of electromagnetic radiation, X-rays and gamma rays are packets of energy (photons) having neither charge nor mass. They have essentially the same properties, but differ in origin. X-rays are emitted from processes outside the nucleus (e.g., bombardment of heavy atoms by fast-moving electrons), whereas gamma rays originate inside the
nucleus (during the decay of radioactive atoms). The energy of ionizing radiation is expressed in electronvolts (eV), a unit equal to the energy acquired by an electron when it passes through a potential difference of 1 volt in a vacuum; 1 eV = 1.6 . 10-19 joules (J) (IARC 2000). The energy of X-rays typically ranges from 5 to 100 keV. Lower in energy than gamma rays, X-rays are less penetrating; a few millimeters of lead can stop medical X-rays. The energy distribution of Xradiation is continuous, with a maximum at an energy about one third that of the most energetic electron. The energy of gamma rays resulting from radioactive decay typically ranges from 10 keV to 3 MeV. Gamma rays often accompany the emission of alpha or beta particles from a nucleus. Because of scattering and absorption within the radioactive source and the encapsulating material, the emitted photons have a relatively narrow energy spectrum (i.e., are monoenergetic). Gamma rays are very penetrating; they can easily pass through the human body, but they also can be absorbed by tissue.

REPORT ON CARCINOGENS, ELEVENTH EDITION

ntp.niehs.nih.gov:8080/query.html?col=030roc&qt=x-ray

[ballscratcher(bnichols)]

(the link to the original document is built into this copy near the end of the paper) The title of this paper is "Low Levels of Ionizing Radiation May Cause Harm" The paper establishes that low level exposure may cause harm and establishes that 10 Rem is a threshold for anticipated cancers.

Read Full Report
Date: June 29, 2005
Contacts: Vanee Vines, Senior Media Relations Officer
Megan Petty, Media Relations Assistant
Office of News and Public Information
202-334-2138; e-mail <[e-mail]>

FOR IMMEDIATE RELEASE

Low Levels of Ionizing Radiation May Cause Harm

WASHINGTON -- A preponderance of scientific evidence shows that even low doses of ionizing radiation, such as gamma rays and X-rays, are likely to pose some risk of adverse health effects, says a new report from the National Academies' National Research Council.

The report's focus is low-dose, low-LET -- "linear energy transfer" -- ionizing radiation that is energetic enough to break biomolecular bonds. In living organisms, such radiation can cause DNA damage that eventually leads to cancers. However, more research is needed to determine whether low doses of radiation may also cause other health problems, such as heart disease and stroke, which are now seen with high doses of low-LET radiation.

The study committee defined low doses as those ranging from nearly zero to about 100 millisievert (mSv) (1 Rem) -- units that measure radiation energy deposited in living tissue. The radiation dose from a chest X-ray is about 0.1 mSv (10 mRem). In the United States, people are exposed on average to about 3 mSv (300 mRem) of natural "background" radiation annually.

The committee's report develops the most up-to-date and comprehensive risk estimates for cancer and other health effects from exposure to low-level ionizing radiation. In general, the report supports previously reported risk estimates for solid cancer and leukemia, but the availability of new and more extensive data have strengthened confidence in these estimates.

Specifically, the committee's thorough review of available biological and biophysical data supports a "linear, no-threshold" (LNT) risk model, which says that the smallest dose of low-level ionizing radiation has the potential to cause an increase in health risks to humans. In the past, some researchers have argued that the LNT model exaggerates adverse health effects, while others have said that it underestimates the harm. The preponderance of evidence supports the LNT model, this new report says.

"The scientific research base shows that there is no threshold of exposure below which low levels of ionizing radiation can be demonstrated to be harmless or beneficial," said committee chair Richard R. Monson, associate dean for professional education and professor of epidemiology, Harvard School of Public Health, Boston. "The health risks – particularly the development of solid cancers in organs – rise proportionally with exposure. At low doses of radiation, the risk of inducing solid cancers is very small. As the overall lifetime exposure increases, so does the risk (red text mine, Bill Nichols)." The report is the seventh in a series on the biological effects of ionizing radiation.

Assessing Health Risks

The committee's risk models for exposure to low-level ionizing radiation were based on a sex and age distribution similar to that of the entire U.S. population, and refer to the risk that an individual would face over his or her life span. These models predict that about one out of 100 people would likely develop solid cancer or leukemia from an exposure of 0.1 Sv (100 mSv) (10 Rem). About 42 additional people in the same group would be expected to develop solid cancer or leukemia from other causes. Roughly half of these cancers would result in death. These particular estimates are uncertain, however, because of limitations in the data used to develop risk models.

Survivors of atomic bombings in Hiroshima and Nagasaki, Japan, were the primary sources of data for estimating risks of most solid cancers and leukemia from exposure to ionizing radiation. The committee's review included an examination of updated cancer-incidence data from tumor registries of the survivors, and of research data on solid cancer deaths -- which is now more abundant because the number of deaths available for analysis has nearly doubled since the Research Council published its previous report on this topic in 1990. The committee combined this information with data on people who had been medically exposed to radiation to estimate risks of breast cancer in women and thyroid cancer. Data from additional medical studies and from studies of people exposed to radiation through their occupations also were evaluated and found to be compatible with the committee's statistical models. Follow-up studies should continue for the indefinite future, the report says.

Adverse hereditary health effects that could be attributed to radiation have not been found in studies of children whose parents were exposed to radiation from the atomic bombs. However, studies of mice and other organisms have produced extensive data showing that radiation-induced cell mutations in sperm and eggs can be passed on to offspring, the report says. There is no reason to believe that such mutations could not also be passed on to human offspring. The failure to observe such effects in Hiroshima and Nagasaki probably reflects an insufficiently large survivor population.

Follow-up studies of people who receive computed tomography (CT) scans, especially children, should be conducted, the report adds. Also needed are studies of infants who are exposed to diagnostic radiation because catheters have been placed in their hearts, as well as infants who receive multiple X-rays to monitor pulmonary development. CT scans, often referred to as whole body scans, result in higher doses of radiation than typically experienced with conventional X-rays.

Sources of Ionizing Radiation

People are exposed to natural background ionizing radiation from the universe, the ground, and basic activities such as eating, drinking, and breathing. These sources account for about 82 percent of human exposure.

Nationwide, man-made radiation comprises 18 percent of human exposure. In this overall category, medical X-rays and nuclear medicine account for about 79 percent, the report says. Elements in consumer products -- such as tobacco, tap water, and building materials -- account for another 16 percent. Occupational exposure, fallout, and the use of nuclear fuel constitute roughly 5 percent of the man-made component nationwide.

Factors that could increase exposure include greater use of radiation for medical purposes, working around radioactive materials, and smoking tobacco. Living at low altitudes, where there is less cosmic radiation, and living and working on the upper floors of buildings, where there is less radon gas -- a primary source of natural ionizing radiation -- are factors that could decrease exposure.

The report was sponsored by the U.S. departments of Defense, Energy, and Homeland Security, the U.S. Nuclear Regulatory Commission, and the U.S. Environmental Protection Agency. The National Research Council is the principal operating arm of the National Academy of Sciences and the National Academy of Engineering. It is a private, nonprofit institution that provides science and technology advice under a congressional charter. A committee roster follows.


Copies of Health Risks from Exposure to Low Levels of Ionizing Radiation (BEIR VII - Phase 2) will be available this summer from the National Academies Press; tel. [phone] or 1-800-624-6242 or on the Internet at www.nap.edu. Reporters may obtain a copy from the Office of News and Public Information (contacts listed above).


[ This news release and report are available at national-academies.org ]


NATIONAL RESEARCH COUNCIL
Division on Earth and Life Studies
Board on Radiation Effects Research

Committee to Assess Health Risks From Exposure to Low Levels of Ionizing Radiation

Richard R. Monson, M.D., Sc.D. (chair)
Associate Dean for Professional Education, and
Professor of Epidemiology
School of Public Health
Harvard University
Boston

James E. Cleaver, Ph.D.(1) (vice chair)
Professor of Dermatology
Cancer Center and Department of Pharmaceutical Chemistry
University of California
San Francisco

Herbert L. Abrams, M.D. (2)
Professor Emeritus of Radiology
Stanford University Medical School, and
Member in Residence
Stanford Center for International Security and Cooperation
Stanford, Calif.

Eula Bingham, Ph.D. (2)
Professor of Environmental Health
University of Cincinnati
Cincinnati

Patricia A. Buffler, Ph.D. (2)
Kenneth and Marjorie Kaiser Chair of Cancer Epidemiology, and
Professor of Epidemiology
School of Public Health
University of California
Berkeley

Elisabeth Cardis, Ph.D.
Chief, Unit of Radiation and Cancer
International Agency for Research on Cancer
Lyon, France

Roger Cox, Ph.D.
Director
National Radiological Protection Board
Chilton, United Kingdom

Scott Davis, Ph.D.
Professor and Chair
Department of Epidemiology
School of Public Health and Community Medicine
University of Washington, and
Full Member
Program in Epidemiology
Division of Public Health Sciences
Fred Hutchinson Cancer Research Center
Seattle

William C. Dewey, Ph.D.
Emeritus Professor of Radiation Oncology
University of California
San Francisco

Ethel S. Gilbert, Ph.D.
Biostatistician
Radiation Epidemiology Branch
National Cancer Institute
Bethesda, Md.

Albrecht Kellerer, Ph.D.
Professor Emeritus
University of Munich
Munich, Germany

Daniel Krewski, Ph.D., M.H.A.
Director
McLaughlin Centre for Population Health Risk Assessment, and
Professor of Medicine and of Epidemiology and Community Medicine
University of Ottawa
Ontario, Canada

Tomas Lindahl, M.D.
Director
Clare Hall Laboratories
Cancer Research U.K.
London

Katherine E. Rowan, Ph.D.
Professor and Associate Chair
Department of Communication
George Mason University
Fairfax, Va.

K. Sankaranarayanan, Ph.D.
Professor Emeritus
Department of Toxicogenetics
Leiden University Medical Centre
Leiden, Netherlands

Daniel W. Schafer, Ph.D.
Professor
Department of Statistics
Oregon State University
Corvallis

Robert L. Ullrich, Ph.D.
Barbara Cox Anthony University Chair in Oncology
Departments of Environmental and Radiological Health Sciences and of Clinical Sciences
Colorado State University
Fort Collins

RESEARCH COUNCIL STAFF

Rick Jostes, Ph.D.
Study Director

Evan B. Douple, Ph.D.
Director
Board on Radiation Effects Research


(1) Member, National Academy of Sciences
(2) Member, Institute of Medicine

[ballscratcher(bnichols)]

This paper challenges (in fact, it refutes the industry's claim) low level exposure to be "safe". The author is Wolfgang Kohnlein; I failed to include a link to the original paper. Look at the table about midway into the paper. Notice how the value of cancer risk from exposure to ionizing radiation has changed since 1972.

Risk Estimates of Low-Level Ionizing Radiation.

There has never been any doubt about the disastrous short - and long-term effects of exposure to high doses of ionizing radiation. However, the public acceptance of billion dollar investments in the fifties and sixties in a runaway build-up of nuclear weapons production, civilian nuclear energy, as well as nuclear medicine, was based on the confident assurances of enthusiastic radiation experts that added exposures at dose levels acceptable to industry would not be found detrimental to human health.

Premature evaluations of the delayed effects of radiation among the Japanese survivors, as well as transference to humans of radiation effects in animals, lead to strongly held optimistic convictions. For decades, any challenge to these tenets based on extrapolations by epidemiologic study among populations with occupational and environmental exposures, were received with enmity and rejection. Nevertheless, optimistic expectations had to be scaled back continuously as the appearance of long delayed excess cancer cases among the Japanese survivor population (see Table 1).

Our present regulations for radiation protection depend almost exclusively on the recommendations of the international commission on radiological protection (ICRP). The ICRP itself relies on published data and recommendation of its subcommittees. The main source of information on radiation risk and radiation hazards is taken from the experience of the atomic bomb survivors. The official risk estimates of this source have changed over the years. In 1977 the ICRP published a figure of 1,25 additional cancer death per 10,000 person cSv. This figure was revised in 1990 to 5. Other organizations and independent scientists arrived at much higher risk estimates (see Table 1).







Table 1: Estimates of the additional cancer deaths per 10,000 person cGy
according to various sources.

Source Cancer death per 10,000 person cGy
BEIR (1972) 1,17 - 6,2
UNSCEAR (1977) 0,7 - 1,7
ICRP (1977) 1,25
BEIR (1980) 1,5 - 5
Charles et al. (1983) 1,0 - 4,4
Preston + Pearce (1987) 5,8 - 18
UNSCEAR (1988) 4,2 - 11
BEIR V (1990) 5,4 - 12,4
Nussbaum + Köhnlein (1990) 25
The population of Hiroshima and Nagasaki was exposed to an acute very short radiation flash and experienced extreme and traumatic hardship in the weeks and months after that event. The very strong and resistant survived the situation at a higher rate than the weaker individuals among the unborn, the very young and the old. Thus the surviving Hiroshima/Nagasaki collective represents an extraordinarily selected healthy population quite, incomparable to a normal city population.

The radiation situation at the working place (Uranium miners, nuclear workers, medical personnel etc.) is completely different from the a-bomb survivors’ exposure. Radiation risk derived from one type of exposure condition cannot be applied to a completely different exposure condition. There is no universal dose effect relationship.

Already for these reasons one has to challenge the normally used procedure of the official commissions. Furthermore the radiation standards were derived from the Hiroshima/Nagasaki cohorts exposed to rather high doses (> 100 cGy). Occupational radiation exposure is normally at much lower doses (< a few cGy per year). Thus for risk estimates at low doses one has to extrapolate from the observed cancer and mutation rates at high doses. Different procedures have been proposed in the past for this extrapolation (see Figure 2). In the last twenty years there has been a steady growth in the number of independent investigations of populations exposed to low level ionizing radiation where adverse health effects have been found. Radiation effects have been confirmed repeatedly in cohorts exposed to diagnostic x-rays, nuclear weapons fallout, and occupational exposure ranging from uranium miners, nuclear dockyard workers, workers in other nuclear facilities to flying personal and cabin attendants of civil air lines.

Time is now running out for the risk estimates supporting the official interagency policy that low-level ionizing radiation is "harmless". The reason for this is that during the "harmless" era there were many unnecessary and avoidable exposures to low-level radiation.

Newer studies reported 0.05 Sv (5 Rem) as the doubling dose for leukemia, lung cancer and other cancer forms while the official estimates in interagency reports are still well over 1 Sv (100 Rem).

This again suggests that the actual risks are more than 20 times the official ones. The agencies responsible for setting radiation protection standards refuse to use the new data for risk estimates because in their opinion the older data like the Japanese A-bomb data is the best available. There is, however, no bio-statistical warrant for this claim. From a scientific standpoint a population of healthy worker who never been exposed to high doses of radiation is much more informative than a population of sick persons or survivors of the A-bomb who may have been exposed to one Sv and more. Continuous and concurrent dosimetry for monitoring uranium miners, nuclear dockyard workers and workers in other nuclear facilities is far superior to retrospective dosimetry that is based on assumptions which are now in serious question. Finally, good statistical practice says that you never extrapolate far beyond the range of the data when good data in the right range is available.

With the much better data and direct risk estimates available today, scientific evaluation of radiation risks should replace the obsolete older estimates by the newer ones. That this did not happen in the latest reports of the official commissions suggests that official estimates are no longer a scientific product but rather a political one.
Table 2: Comparison of the epidemiological data available today with the data used in official reports (Interagency, BEIR, ICRP etc.)

Characteristics of the data Data available today Data used in official reports
Who are the persons under study? Nuclear workers under normal working conditions; Uranium miners; medical X-ray exposed persons Survivors of A-bomb, persons with grave disease requiring therapeutic X-ray
What are the dosages used? Low-level radiation Dosages in most subjects well over 1 Sv
What is the quality of the dosimetry for persons under study? Continuous monitoring of the exposure with the recording of relevant data for each individual Retrospective estimates of exposures without adequate crosschecks or control of the dosimetry
What is the quality of the follow-up for the persons under study? Virtually complete with full deaths certificates and other information Incomplete and often inadequate follow-up and poor quality of information on individuals
What was the quality of information used for comparison? Unexposed reference populations; national standard mortality ratios Biased comparison series (e.g. in some A-bomb comparisons, persons composed up to 0,1 Sv are used as controls)
What assumptions are necessary for estimates of doubling dose or other quantitative measures of health effects? Estimates can be made directly without any strong assumption or extrapolation beyond the range of data available Estimates require assumptions of dubious "linear" or other hypotheses and are merely guesswork
As long as official risk estimates for radiation technologies ranging for Uranium mining to permanent disposal of radioactive waste are different by more than an order of magnitude from those of modern epidemiological studies one has to invoke the "primary principle":

In dealing with potentially hazardous technologies the benefit of the doubt must go to the public and not to the technologies.

In practical terms this means that the critics of a technology must persent present sound evidence of the hazard and after this the burden of proof shifts to the proponents to show that the technology is save.

If we consider that 0.02 Sv (2 Rem) per year exposure is currently allowed for nuclear workers by the national nuclear regulatory commission’s then a doubling dose for lung cancer and leukemia will accumulate within a three years time. A dose that doubles the risk of a fatal disease in such a short time is a serious public health hazard. Since the proponents of nuclear technology failed to prove that such exposures are save permissible doses should reduced drastically as claimed for many years.

Wolfgang Kohnlein

[ HOME | RADIATION | CONTACT ]

[ballscratcher(bnichols)]

From the American Nuclear Society. This is another of the 10 Rem threshold papers.

Health Effects of Low-Level Radiation Position Statement 41 June 2001
AMERICAN NUCLEAR SOCIETY • Outreach Program (708-352-6611) • Federal Affairs (708-352-6611) • www.ans.org
1 of 1
Health Effects of Low-Level Radiation
Position Statement
June 2001
It is the position of the American Nuclear Society that there is insufficient scientific evidence to
support the use of the Linear No Threshold Hypothesis (LNTH) in the projection of the health
effects of low-level radiation.
Given this situation, an independent group of reputable scientists, medical experts and health
researchers should be established to conduct an open scientific review of all data and analyses on
the subject of LNTH. Based on the conclusions of this review group, a separate group composed
of stakeholders should make recommendations on whether adjustments to current radiation
protection guidelines should be made immediately to reflect current information.
In addition, it is the ANS position that new research on low-level radiation health effects,
spanning several disciplines, should be initiated. Meritorious existing research within the
disciplines should continue to receive funding.
While this research proceeds, the ANS concurs with the Position Statement on “Radiation Risk
in Perspective” issued by the Health Physics Society in January 1996, which states as follows:
“In accordance with the current knowledge of radiation health risks, the Health Physics
Society recommends against quantitative estimation of health risks below an individual
dose of 5 rem1 in one year or a lifetime dose of 10 rem in addition to background
radiation. Risk estimation in this dose range should be strictly qualitative accentuating a
range of hypothetical health outcomes with an emphasis on the likely possibility of zero
adverse health effects. The current philosophy of radiation protection is based on the
assumption that any radiation dose, no matter how small, may result in human effects,
such as cancer and hereditary genetic damage. There is substantial and convincing
scientific evidence for health risks at high dose. Below 10 rem (which includes
occupational and environmental exposures) risks of health effects are either too small to
be observed or are non-existent.”
1 The rem is the unit of effective dose. In international units, 1 rem = 0.01 sievert (SV)
__________________________________________
The American Nuclear Society, founded in 1954, is a not-for-profit scientific and educational society of over 11,000 scientists,
engineers, and educators from universities, government and private laboratories, and industry.
Position Statements are the considered opinions and judgments of the Society in matters related to nuclear science and
technology. They are intended to provide an objective basis for weighing the facts in reaching decisions on important national
issues

[ballscratcher(bnichols)]

Here's a link to the city of Austin's (Texas) firefighter early retirement system. Municipalities recognize that an older firefighter is less able to carry-out his duties and, for that reason, have provided for a means of early retirement. This is one of the options we might pursue to remove ourselves (the old guys) from continued exposure. The basics of their early retirement: after twenty years of service and the age of 45. The link:

www.afrs.org/enhancements.htm

[ballscratcher(bnichols)]

Dr Steven Wing is an epidemiologist at the University of North Carolina. His name is routinely referenced during studies of the effects of exposure to low-level ionizing radiation.
This paper was published at the conclusion of one such study and its finding was (quote from the paper) "Additionally, radiation doses received at younger ages were not associated with cancer deaths. However, readings on radiation badges worn by workers when they were ages 55 and above were associated with death rates for cancer, and particularly for lung cancer."
The link :
news.bio-medicine.org/medicine-news-3/Study-shows-importance-of-exposure-age-for-Hanford-nuclear-workers-cancer-risk-9385-3/


CHAPEL HILL -- The ages at which workers are exposed to low doses of ionizing radiation apparently make a difference in whether they will develop cancer, according to a new University of North Carolina at Chapel Hill study.
UNC scientists investigated deaths among workers at the U.S. Department of Energy's Hanford Site in Richland, Wash. The Hanford Site produced plutonium for atomic weapons, including the first plutonium bombs dropped during World War II.
Researchers say the largest cancer risk from older-age exposures is for lung cancer.
"Findings of radiation-related cancer risks among nuclear workers have been questioned in the past by other scientists who concluded that most occupational exposures were too low to cause a detectable increase in cancer rates," said Dr. Steven B. Wing, associate professor of epidemiology at the UNC School of Public Health. "Predictions based on studies of survivors of the atomic bombings of Japan during the war suggested that cancer risks from radiation exposures of Hanford workers would be too small to detect."
The new study evaluated radiation risks by using measurements of workers' radiation exposures recorded on radiation-sensitive badges worn on the job, Wing said. Cancers were identified through death records. Researchers identified 8,153 deaths, including 2,265 from cancer, among 26,389 workers hired between 1944 and 1978 and followed through 1994.
"We found no relationship between radiation doses and deaths from causes other than cancer, primarily heart disease and stroke," he said. "Additionally, radiation doses received at younger ages were not associated with cancer deaths. However, readings on radiation badges worn by workers when they were ages 55 and above were associated with death rates for cancer, and particularly for lung cancer."
A report on the findings appears in the June 17 issue of Occupational and Environmental Medicine, a professional journal. Dr. David B. Richardson, assistant professor of epidemiology, is co-author.
The two found that cancer death rates increased, on average, about 3 percent for every additional rem (a unit of radiation dose) received at ages 55 and above, Wing said. For lung cancer, the increase was about 9 percent per rem. U.S. workers are permitted to receive up to five rem per year, roughly 15 times more than average annual background radiation.
"Findings of increased cancer associated with low-level radiation exposures among nuclear workers are important for several reasons," he said. "Among the considerations are common exposures to radiation from medical procedures, the push for new nuclear power plants and debates over whether to release radioactively contaminated metals into the consumer recycled-metal market."
"Studies of cancer following long-term exposure to low-level ionizing radiation are especially relevant to occupational and environmental protection standards and to compensation programs for radiation-exposed workers and veterans," Richardson said.
As people get older, they may become more susceptible to a variety of exposures, including heat and cold, infections, pharmaceuticals and toxic chemicals, he said. In contrast, researchers studying Japanese A-bomb survivors concluded that older people were less sensitive to radiation-induced cancer.
"Results from Hanford may be different because the older A-bomb survivors had to be especially strong to survive the immediate effects of the blasts," Wing said. "Survival of the fittest could have made radiation appear to be less important among the older survivors."
Older people may be more sensitive to radiation because they already have accumulated a lifetime of exposures to radiation, chemicals and other carcinogens, he said. They already may have gone through some of the cellular transformations that lead to cancer.
"Also, aging brings declines in immune function and the ability to repair genetic damage," Wing said.
Although radiation risks were higher for older workers in the UNC study, it would be inappropriate to conclude that younger people are not at risk, he said. He and Richardson could not examine cancers that did not lead to death, and they could not examine other possible effects of radiation, including genetic damage that could be passed on to children and impacts on developing fetuses.



Contact: David Williamson
919-962-8596
University of North Carolina at Chapel Hill
16-Jun-2005

link:
news.bio-medicine.org/medicine-news-3/Study-shows-importance-of-exposure-age-for-Hanford-nuclear-workers-cancer-risk-9385-3/

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Dr. Steven Wing publishes another paper, this time the research subjects are from Oak Ridge. The conclusion is, once again, that exposure of older workers results in a greater risk of cancer. "Older" in this study is 45 years of age.

International Journal of Epidemiology
International Journal of Epidemiology, Vol 28, 428-436, Copyright © 1999 by International Epidemiological Association
________________________________________
ARTICLES
Greater sensitivity to ionizing radiation at older age: follow-up of workers at Oak Ridge National Laboratory through 1990
DB Richardson and S Wing
Department of Epidemiology, School of Public Health, University of North Carolina at Chapel Hill 27599-8050, USA. [e-mail]
BACKGROUND: Workers at Oak Ridge National Laboratory (ORNL) were individually monitored for whole body exposure to ionizing radiation. Studies of these workers may provide valuable information about the long-term effects of occupational exposure to ionizing radiation. Since biological changes occur as adults age, a potentially important question in these investigations is whether sensitivity to the carcinogenic effects of ionizing radiation changes with age at exposure. METHODS: Vital status and cause of death were ascertained through 1990 for 8307 white males hired at ORNL from 1943 through 1972. Associations between whole body ionizing radiation dose and all-cancer mortality were quantified using life table regression methods for time dependent exposures. Analyses focused of differences in radiation- cancer associations with age at exposure. Length of follow-up, period of hire, and age at risk were considered as alternative explanations for effects of age at exposure. RESULTS: Cumulative radiation dose was associated with a 1.8% (SE = 0.9) increase in all-cancer mortality per 10 mSv, assuming a 10-year lag between exposure and mortality. However, radiation doses received at older ages exhibited larger associations with cancer mortality than doses received at younger ages. Doses received after age 45 were associated with a 5.9% (SE = 1.7) increase in cancer mortality per 10 mSv, adjusted for doses received before age 45. Dose-response associations between cancer mortality and doses received after age 45 appeared consistent across periods of follow-up, periods of hire, and ages at risk. CONCLUSIONS: Findings suggest that sensitivity to the carcinogenic effects of ionizing radiation may increase with older ages at exposure. More attention should be given to the role of age at exposure in studies of the health effects of low- level exposure to ionizing radiation, and to efforts to limit exposure to ionizing radiation.

This article has been cited by other articles:

D B Richardson and J P Ashmore
Investigating time patterns of variation in radiation cancer associations
Occup. Environ. Med., August 1, 2005; 62(8): 551 - 558.
[Abstract] [Full Text] [PDF]

________________________________________

S Wing and D B Richardson
Age at exposure to ionising radiation and cancer mortality among Hanford workers: follow up through 1994
Occup. Environ. Med., July 1, 2005; 62(7): 465 - 472.
[Abstract] [Full Text] [PDF]

________________________________________

D Loomis, D B Richardson, and L Elliott
Poisson regression analysis of ungrouped data
Occup. Environ. Med., May 1, 2005; 62(5): 325 - 329.
[Abstract] [Full Text] [PDF]

________________________________________

D B Richardson
An incidence density sampling program for nested case-control analyses
Occup. Environ. Med., December 1, 2004; 61(12): e59 - e59.
[Abstract] [Full Text] [PDF]

________________________________________

D B Richardson and D Loomis
The impact of exposure categorisation for grouped analyses of cohort data
Occup. Environ. Med., November 1, 2004; 61(11): 930 - 935.
[Abstract] [Full Text] [PDF]

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Todd Newkirk just sent me (4/28/09) some information fresh from the NRC's pages.
NRC is beginning a public comments period about (drum-roll, please) reducing the limit for occupational exposure. ICRP is apparently the motivating force behind the announcement.

That's the good news; the bad news is that the comments period can last as long as three years. Still, the NRC (and ICRP) are moving in the direction that seems pre-ordained.

This link doesn't work until after you've logged-onto the NRC website but I'll provide it anyway. This is the announcement of rule-making changes.
www.nrc.gov/reading-rm/doc-collections/commission/srm/2008/2008-0

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(I've had some feedback that these posts are too long; sorry).
Today's installment (4/29/09) comes from Todd Newkirk. This forum is the blog that he addresses in his e-mail. NRC's proposed rule making is designed to accept input from interested parties via teleconference; this is the Union's opportunity to comment. Here's the entire content of Todd's e-mail:

The commission recommended to the staff to consider lowering annual dose from 5 to 2 R (Option 3) and engage in stakeholder dialogue to keep as is or make the change to 10CFR20. If you have your blog group going, remember many of these public meetings can be participated via teleconference. Normally when IBEW goes and makes comments at the NRC, input is taken and considered from local unions as a whole, then discussed for a position paper from the IP. Sometimes local unions also make their own lobby efforts to rulemaking which often is more pinpointed than the broad terms I engage with the staff for addressing our position on behalf of the IP.

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Yet another link; this one is the NRC's announcement of pending rule making hearings to reduce from 5 Rem to 2 Rem, the annual dose limit:

2008-0197srm OPTION 3 NRC.pdf

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I'm hesitant to copy and paste from work e-mails.
Our Radiation Protection manager recently attended an INPO-hosted RPM workshop. One of the topics that was discussed (and with which CPNPP WILL comply) was the reduction of dose to high-dose individuals. Imagine that. This topic is gaining more and more traction.

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BEIR VII, phase II reports that three Rem is the doubling dose for the incidence of cancer. Does six Rem result in a "quadrupling" risk? Would nine Rem only result in a six-fold increase in cancer risk or would it be an eight-fold increased risk? What are the increased risks associated with lifetime exposures of nine Rem, twelve, fifteen, etc?

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ICRP spends a lot of time addressing the issue of dose received when one is in her/his twenties. They ponder the long-term effects of this dose.
Separately, they engage in the same puzzle regarding dose received while one is in her/his thirties; what will be her/his cancer risk in her/his sixties?
ICRP ponders the question for each decade of one's life but it never asks the question: what will be the outcome of dose received in EACH decade of one's adult life?
ICRP may not be concerned about it but I am and you should be.