tag:blogger.com,1999:blog-8850795848027608997.post5278539566416440..comments2023-11-05T02:15:15.513-08:00Comments on Majia's Blog: Radiocesium in Tokyo Bay from Fukusima Daiichi DisasterMajia's Bloghttp://www.blogger.com/profile/04941091700194936591noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-8850795848027608997.post-65170194296759893882018-06-08T14:37:43.434-07:002018-06-08T14:37:43.434-07:00Better to have scientific evidence than hyperbole ...Better to have scientific evidence than hyperbole or sophistry, even though one may not agree some of it. I wish there were more published by Kaltofen, about radionuclides in air samples, he has gotten.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8850795848027608997.post-49608217072763000302018-06-08T11:01:29.197-07:002018-06-08T11:01:29.197-07:00Hi Majia,
Maximum activities of 137-Cs in sedimen...Hi Majia,<br /><br />Maximum activities of 137-Cs in sediments right offshore Fukushima and along the coast were 540 Bq/kg (http://radioactivity.nsr.go.jp/en/contents/8000/7138/24/425_0807.pdf) and 700 +/- 60 Bq/kg (Sanial et al. 2017, http://radioactivity.nsr.go.jp/en/contents/8000/7138/24/425_0807.pdf). The partitioning/sticking of Cs to the sediments there occurred at seawater concentrations immediately (weeks) following the meltdowns that were millions to 10's of millions of Bq/meter cubed of seawater. Given that seawater concentrations here along the coast of North America are about a million times lower than those peak activities it is very unlikely that 137-Cs from Fukushima can be measured in sediments here along the coast owing to ocean transport of contamination. But I will collect some samples and have a look for you. Atmospheric transport of Fukushima contamination to soils on land was very minor here. Measurements by colleague Kris Starosta and his group show that only about 0.2-0.3 Bg/kg Fukushima derived 137-Cs could be detected. You can read about that study here https://fukushimainform.ca/2018/03/11/monitoring-fukushima-contamination-in-pacific-salmon-and-soil-in-british-columbia/ <br /><br />Sediments here are unlikely to represent a significant vector for radiocesium to make its way into the food web or lead to exposure of human consumers or wildlife to Fukushima contaminants given the scientifically derived evidence already gathered. Anonymoushttps://www.blogger.com/profile/00311506882340000818noreply@blogger.comtag:blogger.com,1999:blog-8850795848027608997.post-8839326111955278452018-06-07T13:11:28.706-07:002018-06-07T13:11:28.706-07:00Japanese English
NAVIGATION
YOU ARE HERE: BACKGROU...Japanese English<br />NAVIGATION<br />YOU ARE HERE: BACKGROUND INFORMATION RELATING TO THE EFFECTS OF IONISING RADIATIONS AND THE FUKUSHIMA DAI-ICHI ACCIDENT REMEDIATION FOLLOWING MAJOR RADIATION ACCIDENTS CHARACTERISTICS OF CAESIUM-134 AND CAESIUM-137<br />Characteristics of Caesium-134 and Caesium-137<br />font size decrease font size increase font size Print<br />Radiological Characteristics<br />Caesium-134 has a radioactive half life of 2.06 years. It decays by beta emission, yielding one beta particle per transformation with a mean energy of 0.157 MeV. It also emits an average of 2.23 gamma rays per transformation with a mean energy of 0.698 MeV.<br /> <br />Caesium-137 has a radioactive half life of 30.2 years. It decays by beta emission, yielding one beta particle per transformation with a mean energy of 0.188 MeV. Its other emissions are negligible. In 0.944 of transformations, barium 137m (radioactive half life 2.552 minutes) is produced. This decays by gamma emission in 0.898 of transformations, emitting a gamma ray of energy 0.662 MeV.<br /> <br />Behaviour of Caesium in Soils and Plants1)2)3)<br />Caesium is a close chemical analogue of potassium and can substitute for it within the structure of clay minerals. Thus, it binds strongly to clays, tending to be both immobile and relatively poorly available to plants in clay rich soils. Conversely, it tends to be more mobile and available in soils that contain little clay and that are potassium deficient.<br /> <br /> Demonstration projects<br /> <br /> Demonstration projects<br /> <br />Demonstration projects<br /> <br />Depth distribution of radioactivity density in soil of schoolsand Playgrounds<br />Behaviour of Caesium in Domestic Animals and Humans1)2)3)<br />Caesium is well absorbed from the gastrointestinal tract of mammals and birds, with the fractional absorption typically being in the range 0.6 to 1.0. The element is then relatively uniformly distributed throughout all organs and tissues of the body, though it is concentrated to a limited degree in muscle, following the distribution of stable potassium. The biological half life of retention in the body differs between species and generally increases with increasing body mass both within and between species. Effective half-life of Cesium-137 in humans is approximately 110 days (ICRP Pub.78).<br /> <br /> Demonstration projects<br />Fractional Systemic Retention of Caesium as a Function of Body Mass (applicable to mice, rats, guinea pigs, hens, dogs, monkeys and humans)<br /> <br /> <br /> <br />References<br />1) Coughtrey, P J and Thorne, M C, Radionuclide Distribution and Transport in Terrestrial and Aquatic Ecosystems, Volume 1, A A Balkema, Rotterdam, 1983<br />2) IAEA-TECDOC-1616, 2009<br />3) IAEA Technical Reports Series No. 472, 2010<br /> <br /> <br /><br />back to top<br />Background information<br /><br />Background Information relating to the Effects of Ionising Radiations and the Fukushima Dai-ichi Accident<br />The Nature of Ionising Radiations and their Health Effects<br />Everyday Exposures to Ionising Radiations<br />Major Nuclear Accidents and Their Consequences<br />International Guidance, Legislation and Regulations<br />Remediation following Major Radiation Accidents<br />Remediation following Major Radiation Accidents<br />Characteristics of Caesium-134 and Caesium-137<br />Remediation of Agricultural Areas<br />Remediation of Semi-natural Areas<br />Remediation of Urban and Other Built Areas<br />Waste Management<br /> Search<br />Top<br />Copyright © 2014 Japan Atomic Energy Agency. All Rights Reserved.<br />Anonymousnoreply@blogger.com