Tag Archives: 137-Cs

Most radioactive caesium fallout on Tokyo from Fukushima accident was concentrated in glass microparticles

by Goldschmidt Conference
Originally published by EurekAlert
26 June 2016

New research shows that most of the radioactive fallout which landed on downtown Tokyo a few days after the Fukushima accident was concentrated and deposited in non-soluble glass microparticles, as a type of ‘glassy soot’. This meant that most of the radioactive material was not dissolved in rain and running water, and probably stayed in the environment until removed by direct washing or physical removal. The particles also concentrated the radioactive caesium (Cs), meaning that in some cases dose effects of the fallout are still unclear. These results are announced at the Goldschmidt geochemistry conference in Yokohama, Japan. Continue reading Most radioactive caesium fallout on Tokyo from Fukushima accident was concentrated in glass microparticles

Art, Aliens, and Radiation: Dr. Cullen at the Vancouver Aquarium

Dr. Cullen participated in a panel discussion about the effects of the tsunami and Fukushima disaster at the Vancouver Aquarium on March 7, 2016. Dr. Cullen’s presentation is between 1:15 and 17:00.

Vancouver Aquarium’s original program announcement.

Screening truffles for radioactivity 30 years from Chernobyl

IMAGE
Miro is a trained truffle dog that belongs to Simon Egli, a co-author of the Biogeosciences paper based at Swiss Federal Research Institute WSL. He’s pictured here with a Burgundy truffle he found in Switzerland. Credit: Simon Egli, WSL

by European Geosciences Union
EurekAlert
Published 25 Feb 2016

Some forest mushrooms, such as wild porcini, can accumulate dangerous levels of radioactivity from the soils they grow in. But until now it was unclear if the same was true for truffles, fungi that range among the most expensive foods in the world. Swiss and German researchers have analysed Burgundy truffles collected in central Europe and found they contain only negligible amounts of radioactive caesium, being safe for consumption. The results are published today (25 February) in Biogeosciences, an open access journal of the European Geosciences Union (EGU).

Continue reading Screening truffles for radioactivity 30 years from Chernobyl

Update: InFORM Monitoring Results For Pacific Salmon Collected Summer 2015

InFORM salmon 2015 river-01
Activities of artificial radiocesium in seawater (2014-2015) and fish (2015) from the northeast Pacific Ocean measured by the InFORM project.  No increase in artificial radionuclides was detected in fish compared to those harvested in 2014.  Approximate range of relevant fish species relative to the contaminated plume of seawater are shown in hashed and dotted lines.  Figure by Dr. Jonathan Kellogg.

Measurements undertaken as part of the InFORM project to look for Fukushima derived radionuclides in fish during our second of three years of monitoring are now complete on an additional 156 fish. Sockeye salmon (Oncorhynchus nerka) and Steelhead Trout (Oncorhynchus mykiss) (as well as some Chinook (Oncorhynchus tshawytscha) and Pink (Oncorhynchus gorbuscha) Salmon) were caught off the west coast of Canada in Summer 2015 as they were returning to their home streams and rivers up and down the coast of British Columbia. Samples of fish were obtained with the cooperation and collaboration of the Champagne and Aishihik, ‘Namgis, Nisga’a, Selkirk, Syilix, Tahltan, Taku River Tlingit, Tr’ondëk Hwëch’in, Wet’suwet’en and Wuikinuxv First Nations. These results add to the first ~100 fish collected and analyzed in 2014.

What we have found so far:

  1. With the exception of 7 fish discussed in point 3 below individual fish were not found to have detectable levels of either 134Cs or 137Cs so average levels were calculated for all fish harvested in a given location.
  2. Similar to 2014, none of the fish from 2015 analyzed thus far were found to contain detectable levels of 134Cs a man-made radionuclide that serves as a fingerprint of the Fukushima disaster.
  3. The average level of 137Cs seen in InFORM 2015 fish samples (0.19 Bq kg-1) is similar to the level observed in the 2014 campaign (0.21 Bq kg-1).  As with 134Cs, the Fukushima disaster resulted in the release of a large quantity of 137Cs. However, 137Cs, which has a longer half-life, was already present in the Pacific Ocean prior to the Fukushima accident because of the nuclear weapons testing fallout.
    • The 137Cs levels observed in the 2015 InFORM samples represent a fraction of the Health Canada guidelines (1000 Bq kg-1) and a fraction of the radiation exposure owing to naturally occurring radionuclides Polonium-210 (210Po) and Potassium-40 (40K) which dominate the ionizing radiation dose to fish consumers.
    • While the average 137Cs concentration remained nearly identical from 2014 to 2015, 7 individual fish (out of 156) have shown a detectable level of 137Cs (ranging from 0.27 to 0.60 Bq kg-1) while individual fish from 2014 were below detection limit. Because no 134Cs was detected in these fish it is not possible to say whether detectable 137Cs can be attributed to Fukushima contamination or simply normal variability in contamination owing to nuclear weapons testing fallout.
  4. What this means is that radioactivity from the Fukushima meltdowns has not been detected in the InFORM fish samples caught in BC waters as of summer 2015.
  5. Neither the 137Cs present in the fish nor the naturally occurring radioisotopes in fish represent a measurable health risk to consumers in Canada.

Measurements of radioactive elements in these fish and from previous years are available for download at the Government of Canada Open Data website. Continue reading Update: InFORM Monitoring Results For Pacific Salmon Collected Summer 2015