Radiation Exposure and Risk

Ionizing radiation damages living things and contaminates the environment, sometimes permanently. Studies have shown increases in cancer around nuclear facilities and uranium mines. Radiation mutates genes which can cause genetic damage across generations.

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Entries by admin (221)

Thursday
Sep062012

NRC's Nuke Waste Confidence EIS will delay reactor licenses for at least two years!

Cover of Beyond Nuclear's pamphlet "A Mountain of Radioactive Waste 70 Years High"The five Commissioners who direct the U.S. Nuclear Regulatory Commission (NRC) have just ordered NRC Staff to carry out an expedited, two-year long Environmental Impact Statement (EIS) process to revise the agency's Nuclear Waste Confidence Decision (NWCD) and Rule. Critics have charged the NWCD is a confidence game, which for decades has prevented environmental opponents of new reactor construction/operation licenses, as well as old reactor license extensions, from raising high-level radioactive waste generation/storage concerns during NRC licensing proceedings, or even in the federal courts. This EIS process and NWCD revision will thus delay any final NRC approval for new reactor construction/operation licenses, or old reactor license extensions, for at least two years.

The Court's ruling mandated that NRC give a "hard look" at the health, safety, security, and environmental risks and impacts of extended (not years or decades, but centuries or even permanent) storage of high-level radioactive waste at reactors sites, in pools and/or dry casks.

The "Mountain of Radioactive Waste 70 Years High" conference in Chicago Dec. 1-3 will serve as a launch pad for generating public comments to NRC on this EIS, as well as to push back against the nuclear establishment's backlash proposals to begin "Mobile Chernobyl" irradiated nuclear fuel shipments by road, rail, and waterway to "consolidated interim storage." See Beyond Nuclear's pamphlet on high-level radioactive waste (cover reproduced at left). More.

Friday
Aug172012

Deception in Sieverts: how a measure of radiation damage can actually be used to hide damage

According to a research letter sent this week in the Journal of the American Medical Association (JAMA), levels of internal cesium contamination after Fukushima are “low…much lower than those reported in studies years after the Chernobyl incident”.  However, longer-term, internal exposure to even low levels of cesium can cause a range of diseases and pre-disease conditions, including cancer. The contamination levels found in the people examined in this research are within this range of concern.

For this letter to the editor (Tsubokura, et al.) researchers used actual counts of gamma radiation coming from people’s bodies. Roughly, this count per second of gamma (given in the unit Becquerels or Bq) is then divided by the person’s weight, given in kilograms (kg).  This gives a whole body count that is used to derive the amount of radioactive cesium inside the person.  While not entirely a direct measurement, fewer assumptions and estimates are associated with Bq/kg than with the more highly favored Sievert (Sv).

The Sievert is an estimate of radiation damage based on a number of assumptions (not all of which are correct or applicable to any specific individual) and can end up hiding health damage depending on how it is used.  In this letter, the researchers claim that, even though some cesium concentrations were as high as 196.5 Bq/kg, just one person had an estimated dose above 1.0 millisievert (mSv) – a dose that is considered low by nuclear experts. That dose was 1.07 mSv.

However, in the early 2000’s, a medical doctor in Belarus, Yuri Bandajevski, examined 3000-4000 tissue samples from approximately 400 deceased individuals. Disease or pre-disease conditions were compared to radioactive cesium contamination levels (in Bq/kg) of those same individuals. He replicated his results in animals and also examined a number of living people. There were strong associations between (pre-) pathologies observed, and cesium contamination levels in Bq/kg, across all study subjects.

Bandajevski says “We should pay particular attention to the fact that the presence of even relatively small amounts of Cs-137 in children from 10-30Bq/kg…leads to a doubling in the number of children with electrocardiographic disorders.” Cesium-137 can cause “…in relatively small doses (20-30 Bq/kg); a breach of the regulatory processes in the body. This contributes to the emergence of pathological processes and diseases. This emergence is based on the latent genetic predisposition due to mutagenic action, including the same Cs-137, on gametes of the parental generation.”

For children, the  Tsubokura letter says the concentration of cesium ranges from 2.8 to 57.9 Bq/kg, which is within the range of concern shown, including impacts on the heart and hormone imbalance shown in the Belarus studies.

Therefore, to imply that internal cesium contamination at the levels found after Fukushima are low and of little concern, doesn’t account for what previous research has demonstrated based on the Bq/kg measurement. And while nuclear experts and proponents can claim that 1 millisievert is a “small” amount, it is obviously well within the range that can cause health problems. These health problems can be compounded with continued exposure, to even small amounts of cesium, across generations, indicating that the longer someone stays in a contaminated area, eats contaminated food and/or raises a family in these conditions, the more damage will accumulate and the more, even what were once considered small doses, will have great detriment on health.

In this way, the Sievert as a unit of damage is obviously not precise or foolproof enough to accommodate the many natural variations among humans and exposure scenarios. It can, in fact, lead to misleading assessments about just how dangerous exposure to radioactivity is. A more direct measurement like Bq/kg equated with disease is, at least for cesium, a much truer representation of damage.

Friday
Jul272012

TEPCO subcontractor used lead to fake dosimeter readings at Fukushima plant

replica of lead plate believed to be used to shield dosimiters thus falsifying worker doseWorkers at the crippled Fukushima No. 1 nuclear plant were ordered to cover their dosimeters with lead plates to keep radiation doses low enough to continue working under dangerous conditions, the Asahi Shimbun has learned.

Some refused the orders. Others raised questions about their safety and the legality of the practice. But the man in charge, a senior official of a subcontractor of Tokyo Electric Power Co., warned them that they would lose their jobs--and any chance of employment at other nuclear plants--if they failed to comply. Asahi Shimbun

See also Ministry to search for dosimeter shields at Fukushima plant

Officials of the Health, Labor and Welfare Ministry will search for lead plates that workers at the crippled Fukushima No. 1 nuclear power plant used to shield their dosimeters and later discarded on the plant grounds.

Wednesday
Jul182012

Now 35.8% of Fukushima children examined have thyroid cysts or nodules

Of more than 38,000 children tested from the Fukushima Prefecture in Japan, 36 percent have abnormal growths – cysts or nodules – on their thyroids a year after the Fukushima nuclear disaster, as reported by ENENews. The shocking numbers come from the thyroid examination section of the "Sixth Report of Fukushima Prefecture Health Management Survey," published by Fukushima Radioactive Contamination Symptoms Research (FRCSR) and translated by the blog Fukushima Voice.  Shunichi Yamashita, M.D., president of the Japan Thyroid Association, sent a letter to members in January with guidelines for treating thyroid abnormalities. In 2001 Yamashita co-authored a study that found normal children in Nagasaki to have 0 percent nodules and 0.8 percent cysts. The introduction of the letter, written by Fukushima Voice, states that the results in Fukushima show a "much faster progression compared to Chernobyl" as research done around Chernobyl showed the rate of thyroid nodules in children 5 to 10 years after the accident to be 1.74 percent. Business Insider and ENE News.

Tuesday
Jul172012

Investigation Sought of Extensive F.D.A. Surveillance on Scientists Who Warned of Radiation Exposure from Medical Devices

"...The New York Times disclosed in an article on Sunday that the agency’s surveillance of five of its own scientists beginning in 2010 had produced 80,000 pages of intercepted e-mails and other documents, along with what amounted to an enemies list of 21 “actors” at the agency, in Congress, the news media and academia who were thought to be collaborating to put out confidential information damaging to the reputation of the F.D.A.’s medical device reviews.

...The F.D.A. scientists maintained that a number of medical imaging devices used to detect colon and breast cancer used unsafe levels of radiation. The special counsel’s office, which rejects the vast majority of the public safety claims that federal employees make, found that the concerns were valid enough to warrant a full investigation, and it sent the matter to Ms. Sebelius to conduct the review. She is scheduled to report back by the end of July, although the deadline may be extended.

...In a confidential memo in May, the Office of Special Counsel, which handles federal workplace grievances, found a “significant likelihood” that the devices posed “a substantial and specific danger to public safety” as the scientists had warned." New York Times