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" ... we know that doing 62 million scans every year for a population of 300 million is not just unnecessary and wasteful, but it's dangerous. It's producing tens of thousands of cancers."-- Dr. Atul Gawande, Dana-Farber Cancer Institute, on NPR's Morning Edition, Sept. 3, 2009 Medical CT and PET scanners expose at least four million North Americans to high doses of radiation each year, a new study shows. Around 400,000 of them get very high doses, higher than the maximum annual doses allowed for nuclear reactor or nuclear weapon site workers, or anyone working with radioactive materials, according to an article in The New England Journal of Medicine (August 27, 2009), "Exposure to Low-Dose Ionizing Radiation from Medical Imaging Procedures."

" ... we know that doing 62 million scans every year for a population of 300 million is not just unnecessary and wasteful, but it's dangerous. It's producing tens of thousands of cancers."-- Dr. Atul Gawande, Dana-Farber Cancer Institute, on NPR's Morning Edition, Sept. 3, 2009 Medical CT and PET scanners expose at least four million North Americans to high doses of radiation each year, a new study shows. Around 400,000 of them get very high doses, higher than the maximum annual doses allowed for nuclear reactor or nuclear weapon site workers, or anyone working with radioactive materials, according to an article in The New England Journal of Medicine (August 27, 2009), "Exposure to Low-Dose Ionizing Radiation from Medical Imaging Procedures."

"I feel that former President Jimmy Carter should come forth with all of the facts surrounding the Three Mile Island Accident, especially those which involved the radiation release and the dose to the public. This disclosure should, moreover, be in language which can be easily and correctly understood by the public, and not massaged to hide the truth. After the accident, for example, I found that the dose officially assigned to the public, was called: "measured dose to the public from the accident" - where "measured" meant it only included the dose after the rate matres were in place the third day after the accident began; "accident" meant that the radiation dose received during the same time period in 1978 when the TMI reactors were all operating and there was Chinese nuclear test fallout, could be subtracted.

"The U.S. National Academy of Sciences (NAS) has repeatedly affirmed that any exposure to radioactivity, no matter how small, carries a health risk. In its 2006 BEIR VII report ("Biological Effects of Ionizing Radiation," 7th iteration), NAS even reported mounting evidence that low dose radiation carries a supra-linear health hazard. That is, low doses are disproportionately more harmful, per unit dose, than high dose radiation. The bottom line is, exposure to low dose radiation, such as intentional "routine" discharges or "accidental" leaks of tritium into the Connecticut River and downstream drinking water supplies and food chains, risks human and wildlife health impacts. The U.S. Environmental Protection Agency's 20,000 picocuries per liter limit on tritium in drinking water is not a conservative health standard. The state of California has a goal to limit tritium in drinking water to 400 picocuries per liter, a fifty-fold strengthening. The state of Colorado's goal is 500 picocuries per liter, a forty-fold strengthening. EPA's and the U.S. Nuclear Regulatory Commission's (NRC) radiological health standards are inappropriately based on "Reference Man" faulty assumptions, which leaves more vulnerable women, children and fetuses at increased risk."

"The maximum radiation dose that might have been received by a child due to a leak of tritiated water at Vermont Yankee was .000072 percent of the average annual dose received from natural sources, according to a document submitted by Entergy, which owns and operates the nuclear power plant in Vernon, to the Nuclear Regulatory Commission. According to the report, consumption over a one-year period of fish from the Connecticut River or vegetables, beef and milk raised with river water would have resulted in a one-year dose of .00026 millirems. The average daily dose to humans from natural sources is 360 millirems. Entergy's dose calculations have been verified to be accurate and are "a small fraction of the regulatory requirement of 3 mrem per year," according to a Ground Water Monitoring Inspection Report released by the NRC on Thursday. "

A mathematical model constructed by researchers at Imperial College London predicts the risk of cardiovascular disease (heart attacks, stroke) associated with low background levels of radiation. The model shows that the risk would vary almost in proportion with dose. Results, published October 23 in the open-access journal PLoS Computational Biology, are consistent with risk levels reported in previous studies involving nuclear workers. Cardiovascular disease is the leading cause of death and one of the leading causes of disability in developed countries, as reported in the paper and also by the World Health Organization (http://www.who.int/whosis/en/). For some time, scientists have understood how high-dose radiotherapy (RT) causes inflammation in the heart and large arteries and how this results in the increased levels of cardiovascular disease observed in many groups of patients who receive RT. However, in the last few years, studies have shown that there may also be cardiovascular risks associated with the much lower fractionated doses of radiation received by groups such as nuclear workers, but it is not clear what biological mechanisms are responsible.

A mathematical model constructed by researchers at Imperial College London predicts the risk of cardiovascular disease (heart attacks, stroke) associated with low background levels of radiation. The model shows that the risk would vary almost in proportion with dose. Results, published October 23 in the open-access journal PLoS Computational Biology, are consistent with risk levels reported in previous studies involving nuclear workers. Cardiovascular disease is the leading cause of death and one of the leading causes of disability in developed countries, as reported in the paper and also by the World Health Organization (http://www.who.int/whosis/en/). For some time, scientists have understood how high-dose radiotherapy (RT) causes inflammation in the heart and large arteries and how this results in the increased levels of cardiovascular disease observed in many groups of patients who receive RT. However, in the last few years, studies have shown that there may also be cardiovascular risks associated with the much lower fractionated doses of radiation received by groups such as nuclear workers, but it is not clear what biological mechanisms are responsible.

The risk of mortality from leukaemia and cancer among radiation workers increases with dose, according to a study. Findings were based on a study of records of more than 175,000 radiation workers on the National Registry for Radiation Workers, which suggest that high doses of more than 0.6 Sieverts could triple the risk of leukaemia. The risk of cancer excluding leukaemia increased by 20% after radiation doses higher than 0.6 Sieverts, according to the research. Workers in the study were employed by organisations such as the Atomic Weapons Establishment, British Nuclear Fuels plc, the Ministry of Defence, Rolls Royce Submarines and the UK Atomic Energy Authority.

The Nuclear Regulatory Commission (NRC) is denying the petition for rulemaking (PRM) filed by Mr. Raymond A. Crandall on May 17, 2007, and docketed on June 22, 2007 (Docket No. PRM-50-87). In his petition, the petitioner requested that the NRC amend the regulations that govern domestic licensing of production and utilization facilities to eliminate the specific criteria related to the radiological doses for control room habitability at nuclear power plants. The petitioner stated that the current deterministic radiological dose requirements for control room habitability have resulted in several negative safety consequences, including an increased risk to public safety. He requested that the NRC delete the 5 rem whole body dose limit and the 0.05 sievert (Sv) (5 rem) total effective dose equivalent (TEDE) limit specified in the current regulations.

Background The growing use of imaging procedures in the United States has raised concerns about exposure to low-dose ionizing radiation in the general population. Methods We identified 952,420 nonelderly adults (between 18 and 64 years of age) in five health care markets across the United States between January 1, 2005, and December 31, 2007. Utilization data were used to estimate cumulative effective doses of radiation from imaging procedures and to calculate population-based rates of exposure, with annual effective doses defined as low (≤3 mSv), moderate (>3 to 20 mSv), high (>20 to 50 mSv), or very high (>50 mSv).

EPA Issues Final Yucca Mountain Radiation Standards (9/30/08) EPA has established radiation standards for the proposed spent nuclear fuel and high-level radioactive waste disposal facility at Yucca Mountain, Nevada. EPA is required to set standards consistent with the findings and recommendations of the National Academy of Sciences (NAS) and satisfy a July 2004 court decision to extend the standards' duration. The Yucca Mountain standards are in line with approaches used in the international radioactive waste management community. The final standards will: * Retain the dose limit of 15 millirem per year for the first 10,000 years after disposal; * Establish a dose limit of 100 millirem annual exposure per year between 10,000 years and 1 million years; * Require the Department of Energy (DOE) to consider the effects of climate change, earthquakes, volcanoes, and corrosion of the waste packages to safely contain the waste during the 1 million-year period; and * Be consistent with the recommendations of the NAS by establishing a radiological protection standard for this facility at the time of peak dose up to 1 million years after disposal.

This database is currently being developed by the U.S. Nuclear Regulatory Commission's (NRC) Office of Nuclear Regulatory Research to track annual aqueous and atmospheric effluent release data and offsite doses calculated for each nuclear power plant in the United States. Effluent release data and calculated doses to individuals offsite are submitted annually to the NRC in accordance with requirements outlined in 10 CFR 50.36(a)(2). Further discussion of these reports can be found in Regulatory Guide 1.21, which can be accessed through the NRC's website. Effluent and dose data are entered directly from the annual reports submitted by each licensee. Questions related to a specific plant should be directed to the NRC Project Manager for that particular plant. General questions about the database should be directed to the Office of Public Affairs.

In the context of disposal of radioactive waste, a performance assessment is a quantitative evaluation of potential releases of radioactivity from a disposal facility into the environment, and assessment of the resultant radiological doses. The term performance assessment can refer to the process, model, or collection of models used to estimate future doses to human receptors. Typically, a performance assessment is conducted to demonstrate whether a disposal facility has met its performance objectives. In general, a performance assessment considers the following factors: * Selected scenario (specific features and processes at the disposal facility and in the surrounding area, such as the location of the potential release, location and general characteristics of the receptors, and applicable transport pathways through which radionuclides might reach the environment and pose a threat to the selected receptor groups) * Performance of the cask or other engineered barrier system used to store low-level waste, limit the influx of water, and reduce the release of radionuclides * Release and migration of radionuclides through the engineered barrier system and geosphere (those deep-underground portions of the disposal facility where human contact is generally not assumed to occur) * Radiological dose(s) to the selected receptor group(s)

A study suggests some younger Americans may be getting too many imaging tests that expose them to worrisome amounts of radiation, which over a lifetime may raise their risk of cancer. Here are some procedures that deliver the biggest doses of radiation: * Myocardial perfusion scans, done in patients with heart disease to see how much blood is getting to the heart muscle. For the test, patients are injected with a small amount radioactive liquid. The test on average delivered 15.6 millisieverts of radiation per dose, and accounted for more than 22 percent of the total radiation exposure among people in the study, more than any other test. For people living in the United States, the normal expected radiation dose from chemicals in the ground or flying in an airplane is 3 millisieverts a year.

Mortality and cancer incidence were studied in the National Registry for Radiation Workers in, relative to earlier analyses, an enlarged cohort of 174 541 persons, with longer follow-up (to 2001) and, for the first time, cancer registration data. SMRs for all causes and all malignant neoplasms were 81 and 84 respectively, demonstrating a 'healthy worker effect'. Within the cohort, mortality and incidence from both leukaemia excluding CLL and the grouping of all malignant neoplasms excluding leukaemia increased to a statistically significant extent with increasing radiation dose. Estimates of the trend in risk with dose were similar to those for the Japanese A-bomb survivors, with 90% confidence intervals that excluded both risks more than 2-3 times greater than the A-bomb values and no raised risk. Some evidence of an increasing trend with dose in mortality from all circulatory diseases may, at least partly, be due to confounding by smoking. This analysis provides the most precise estimates to date of mortality and cancer risks following occupational radiation exposure and strengthens the evidence for raised risks from these exposures. The cancer risk estimates are consistent with values used to set radiation protection standards.

Collectively, Americans now receive more than twice as much radiation each year as in the 1980s. That's according to a new tally by the National Council on Radiation Protection and Measurements. Of course, the operant word here is collectively. NCRP isn't saying every individual is getting twice as big an annual radiation dose, only that if you sum up doses to the entire population each year, that big figure has doubled and more over the past two decades or so. A burgeoning population accounts for 30 percent of the increase, notes Ken Kase, who chaired the NCRP panel that prepared the report. The rest of the increase stems largely from an increase in medical procedures that rely on radiation - from conventional diagnostic X-rays and CT scans to radiotherapy for cancer. Kase, a semi-retired health physicist and senior vice president of NCRP, describes his team's findings in a Q&A appearing in the May Health Physics News.

"Most scientists in this field agree that there is danger even in small doses of radiation" You reported the view that radiation risks are exaggerated, but left out vital information on radiation protection (Radiation health threat overstated - Oxford professor, 11 January). The article relied upon and extensively cited a retired ­professor of particle physics, Wade ­Allison, who is neither a radiation ­biologist nor an epidemiologist, and is not in my view an expert in radiation risks. Indeed, the other three scientists quoted in the article pointedly refrained from supporting Allison. His sole contribution to the literature is a self-published book. An article alongside (Nuclear theory: the current consensus) states that "a single dose below 100 millisieverts (mSv) is usually considered safe", and later gives Allison's claim that "there is a threshold of about 200 mSv, below which the body can repair all DNA ­damage caused and, therefore, which is safe". But there is no safe dose of ­radiation: no matter how low it is, a small risk remains."

"The prostate cancer program at the Veterans Affairs Department's medical center in Philadelphia, where 97 patients were given an incorrect radiation dose, went four years without a peer review or quality assessment, the agency's internal watchdog said Monday. The inspector general for the Veterans Affairs Department also found that computer problems kept several patients under treatment for cancer from receiving a check to make sure they received the correct dose. The inspector general recommended that standardized procedures be implemented throughout the VA. It also said the agency should follow-up to ensure patients who received too low of a dose receive appropriate care."

County public health officials are offering free doses of the radiation-blocking drug potassium iodide to people who live and work downwind of Diablo Canyon nuclear power plant. The pills, also known by their chemical name KI, are available at six locations. They are only to be taken at the direction of public health officials in the event of a radiation leak at Diablo Canyon. The county has enough doses to cover hundreds of thousands of people, said Michelle Shoresman, spokeswoman for the county public health department. They will be available as long as supplies last, which should be a year or so.

County public health officials are offering free doses of the radiation-blocking drug potassium iodide to people who live and work downwind of Diablo Canyon nuclear power plant. The pills, also known by their chemical name KI, are available at six locations. They are only to be taken at the direction of public health officials in the event of a radiation leak at Diablo Canyon. The county has enough doses to cover hundreds of thousands of people, said Michelle Shoresman, spokeswoman for the county public health department. They will be available as long as supplies last, which should be a year or so.

The Nuclear Regulatory Commission has approved a final rule incorporating the Environmental Protection Agency's radiation protection standards for the proposed high-level waste repository at Yucca Mountain, Nev., for the period beyond 10,000 years and up to 1 million years. The rule, to be published soon in the Federal Register, makes NRC's regulations for the repository in 10 CFR Part 63 consistent with the EPA's revised standards, as required by law. The EPA's final standard was issued Sept. 30, 2008. The EPA's revised standards and the NRC's rulemaking were required by the July 9, 2004, ruling of the U.S. Court of Appeals for the D.C. Circuit, which overturned EPA's earlier standard that limited the compliance period to 10,000 years. EPA published its proposed revisions Aug. 22, 2005, and NRC published a proposed rule adopting EPA's revisions and requesting public comment on Sept. 8, 2005. The Federal Register notice with NRC's final rule includes the NRC staff's responses to public comments on the proposed rule, as well as a regulatory analysis of the final rule. The final rule retains EPA's standard dose limit for individuals of 15 millirem for the first 10,000 years after disposal and adopts EPA's 100 millirem dose limit for the period after 10,000 years and up to 1 million years. It will be posted on the NRC Web site here: http://www.nrc.gov/reading-rm/doc-collections/fedreg/notices/. The rule will become effective 30 days following publication.

Radiation from x-rays and CT scans can accumulate to substantial doses, according to a study that estimates as many as 4 milion adults have high exposure ATLANTA - Many types of medical imaging procedures, such as x-rays, computed tomography scans, and nuclear medicine scans, expose patients to ionizing radiation, which over time can accumulate to substantial doses, according to a study published this week in the New England Journal of Medicine. "We know that radiation is not benign and some people are getting high exposures," says Reza Fazel, M.D., the lead author of the study and a cardiologist at Emory University.

"Exposure to radiotherapy or radiation-based diagnostics like computed tomography (CT scans) in early childhood increases breast cancer risk in adulthood, a new study in the Jan 2010 issue of Cancer Epidemiology, Biomarkers & Prevention. The study involved women exposed to thymic irradiation during infancy from 1926 to 1957. Breast cancer was identified in 96 treated in an average dose of 0.71 Gy and 57 untreated women during 159,459 person-year follow-up. Adams MJ and colleagues from University of Rochester School of Medicine and Dentistry found women who were treated by radiation were 200 percent more likely to develop breast cancer than those who did not receive radiation. Higher doses of radiation were linked to high risk of breast cancer."