The disastrous nuclear reactor accident at Fukushima Dai-ichi (number one) Nuclear Power Station on the Pacific coast 120 miles north of Tokyo is nearing its second anniversary. As a consequence of the loss of all electric power after the Tohoku-Chihou-Taiheiyou-Oki Earthquake and Tsunami on March 11, 2011, nuclear fuel melted down in three of the station's six reactors.
Aerial view of Fukushima Daiichi Nuclear Power Station on March 24, 2011, after hydrogen explosions devastated the upper floors of the reactor buildings of Units 1 (background), 3 and 4 (foreground) in the wake of the March 11 earthquake and tsunami. Unit 4 was offline for inspection. TEPCO believes that hydrogen seeped into its building from Unit 3 via standby gas treatment system piping. The building of Unit 2 lost a blowout panel on the eastern side and was spared (courtesy cryptome.org).
Destructive hydrogen explosions severely damaged the facilities. The amounts of radioactivity released into the environment has been surpassed only by the Chernobyl reactor accident of 1986. Residents near the plant were exposed to radioactive fallout while evacuating the area. The immediate surroundings of the power station and the region affected by the plume of airborne radioactivity remain highly contaminated today. Roughly 80,000 residents living in the government-declared exclusion zones are not permitted to return home permanently. Only daytime visits are allowed on occasion (see Chris Meyers' report with the title "A year on, only brief home visits for Japan nuclear evacuees" published online by Reuters Feb. 13, 2012). The International Medical Corps aptly summarizes the challenges the evacuees have faced on its Fukushima Prefecture Fact Sheet.
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| Gamma radiation-based contamination map (high: orange; low: blue; dose rates can be obtained from the IMC Fukushima Prefecture fact sheet) showing the plume area, radii of the 12- and 15-mile evacuation zones as well as of the 50-mile ingestion zone US citizens were advised to avoid (source: NNSA). |
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| Birdseye view of Fukushima Dai-ichi Nuclear Power Station in February, 2013. Unit 1 (top, left) has been enshrouded in a tent-like structure to control gassous radioactive effluents. The refueling floor of Unit 4 (top; right) has been cleared in preparation for a new roof structure. TEPCO is in the process of clearing debris off the refueling floor of Unit 3 (left of Unit 4). Note the sprawling tank farm for the storage of contaminated cooling water (source: House of Japan). |
Now, that we are nearing the two-year milestone, the international media have begun to gauge the current state of affairs in Fukushima. In her article with the title "Unexpected Post-Fukushima Health Woes: Depression, Obesity" posted on CommonHealth Reform and Reality Feb. 15, 2013, guest contributor Judy Foreman writes that no noticeable direct effects on public health could be attributed to the exposure to ionizing radiation. She tells us furthermore that an international panel of experts concluded that the estimated effective absorbed doses were too small to warrant any concerns for public health. Rather, the experts warned that radiophobia is deeply affecting people, developing into the preeminent medical condition threatening public health. Ms. Foreman notes depression and obesity are on the rise in Fukushima Prefecture, while Geoff Brumfiel reported in his news feature with the title "Fukushima: Fallout of fear" published online by the journal Nature Jan. 16, 2013, that depression, anger and anxieties were prevalent among the displaced.
Phobia is defined as irrational, disproportional fear. Radiophobia represents the irrational, disproportional fear of ionizing radiation. This diagnosis does not seem to pertain to the evacuees from Fukushima who must face fears of the actual consequences of the radiological catastrophe every day. Their fears seem neither irrational nor disproportional.
Absorbed radiation dose estimates available to date for the people of Fukushima must be met with caution. No resident around the Fukushima Dai-ichi Nuclear Power Station wore a dosimeter when the fallout rained down. In their preliminary Dose Assessment Report published last summer, radiation experts convened by the World Health Organization had to resort to computational models to estimate effective absorbed dose averages for the examined population. The averages were extrapolated from recordings of a handful of functional monitoring stations scattered across the prefecture. The recordings were incomplete. The available data did not cover the earliest hours of the accident (see The Mainichi article with the title "Fukushima radiation spread to residential areas hours before venting" published online Feb. 22, 2013). Moreover, it does not account for local variations and the contribution of human activity to individual effective absorbed doses.
Individual absorbed doses may depend profoundly on whether the person was indoors or outdoors at the time of the radioactive fallout, whether residents who stayed indoors were well insulated from the outside air, what produce a person consumed in the days and weeks after the releases, i.e. fresh home-grown groceries harvested in the garden and freshly-caught fish or prepackaged food bought in stores, as well as the source of water consumed. Moreover, medical predisposition, gender and age may have influenced how much radioactivity was incorporated and remains in the body.
Personal whole body counts were not performed early enough after the accident to directly capture the internal exposure to ionizing radiation emitted by incorporated short-lived radionuclides. By contrast, cesium-137 with a comparatively long half-life of 30 years is still concentrating in crops, vegetables, mushrooms and life stock and will persist to threaten the human food chain. A quarter century after the Chernobyl reactor accident, Bavarian wild boar stew must remain off the dinner table because the meat's radioactive cesium content is deemed unsafe for human consumption (see Charles Hawley's report with the title "A Quarter Century after Chernobyl: Radioactive Boar on the Rise in Germany" published by Spiegel International Online Jul. 30, 2010). In Japan, continuously emerging hot spots of cesium contamination may pose ever new local health risks for decades to come, requiring unrelenting, meticulous clean-up as well as persistent, diligent crop and life stock controls.
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| Thyroid cancer rates in Belarus after the Chernobyl reactor accident (source: S. Yamashita). |
Furthermore, yet unrecognized long-latency effects may progressively attain prevalence. Pets abandoned in the exclusion zone of Fukushima are frequently found ravaged by viral infections. Though the infections might have mainly been the result of the harsh living conditions in the zone (see Jenny Marder's post with the title "What's the Fallout for Dogs Near Fukushima?" published online by PBS Newshour's Rundown Nov. 10, 2011), high infection rates may suggest that immune responses have been compromised, possibly because of the protracted exposure to low-level ionizing radiation (Manda and others, 2012).
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Cat rescued from the Fukushima exclusion zone showing symptoms of a severe viral infection around nose and eyes (source: Touhoku inunekokyuen).
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References
- Demidchik YE, Saenko VA, Yamashita S (2007) Childhood thyroid cancer in Belarus, Russia, and Ukraine after Chernobyl and at present. Arq Bras Endocrinol Metab 51:748-762.
- Manda K, Glasow A, Paape D, Hildebrandt G (2012) Effects of ionizing radiation on the immune system with special emphasis on the interaction of dendritic and T cells. Front Oncol 2:102.
I thank the contributors of SimplyInfo.org without whom I could not have written this post.
