Tag Archives: Weapons Testing

No radiation from Japan’s Fukushima disaster found in BC fish

No radiation from Japan's Fukushima disaster found in B.C. fish
John Nightingale, president of the Vancouver Aquarium, said at a 2014 news conference by the Arctic char tank at Vancouver Aquarium that radiation levels are barely above background levels since the 2011 meltdown of nuclear reactors at Fukushima caused by the earthquake and tsunami.

By Bethany Lindsay
Vancouver Sun
Published 23 Feb 2016

Nearly five years after a massive earthquake resulted in the Fukushima nuclear disaster in Japan, researchers in B.C. have found no detectable levels of contamination in fish along the West Coast.

Continue reading No radiation from Japan’s Fukushima disaster found in BC fish

The Impact of the Fukushima on Canada: Health Canada Reports

By Jay T. Cullen

The purpose of this post is to bring to the attention of interested readers a recently released report that provides comprehensive account of the environmental radiation surveillance activities conducted by Health Canada in the months immediately following the Fukushima accident.  This report includes an assessment of the overall levels of contamination and resulting impacts to the health of Canadians.  Contrary to irresponsible and inaccurate rumors that Health Canada suspended monitoring in the wake of the triple meltdowns, monitoring activities were, in fact, enhanced and expanded to increase the flow of information and improve understanding of the implications of the contamination for environmental and public health.  While there was no discernible change in total background radiation a distributed system of monitoring stations and the rapid collection and measurement of environmental samples tracked the trace levels of atmospheric contamination across the country. The report concludes:

  1. conservative estimates of the maximum individual dose from Fukushima was less than 0.0003 (1/ 3,000) of the typical annual dose for a Canadian owing to natural background sources
  2. the additional dose resulting from Fukushima derived contamination is far less than the normal variation in dose from place to place in Canada
  3. there are likely to be no health impacts related to this small, incremental dose

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More Citizen Science Seawater Monitoring Results: No Fukushima Contamination Detected

By Jay T. Cullen

@JayTCullen and @FukushimaInFORM

February 16, 2015

What we found:

The absence of any detectable 134-Cs (an unambiguous fingerprint isotope of Fukushima contamination) in the seawater samples indicates that as of November 2014 these locations covering the length of the British Columbia coast have not be affected by ocean currents carrying Fukushima contamination.

The detection limit for 134-Cs averages ~0.2 Bq m-3

Newly added results come from seawater samples collected in collaboration with citizen scientists at the following locations in British Columbia, Canada during November 2014.

  1. Bamfield
  2. Masset, Haida Gwaii
  3. Lax Kw’alaams

Samples were processed and the amount of gamma emitting isotopes determined using a high purity germanium detector.  We look primarily for radioisotopes of cesium (134-Cs half life ~2 years and 137-Cs half life ~ 30 years) for the following reasons:

  1. 134-Cs has a half life that is short enough that all other human sources to the environment have decayed away making it an ideal tracer for Fukushima contamination
  2. next to the short lived Iodine-131 (half life ~ 8 days), Cs isotopes were released in greatest activity to the environment from Fukushima and would be most likely to represent a radiological health risk given their chemistry and propensity to be taken up by the biota
  3. other isotopes were released in much lower amounts from Fukushima relative to Cs (see other posts here and search for plutonium and strontium for example) and would therefore be much more difficult to detect
  4. because they are gamma emitters (unlike Pu isotopes and 90-Sr which emit alpha and beta radiation respectively) they are relatively easy and resource efficient to detect

The absence of detectable 134-Cs indicates that waters near these locations spanning the length of British Columbia have not been contaminated with Fukushima radioactive elements transported across the Pacific by prevailing currents as of Nov 2014. The presence of 137-Cs is due to historical sources of this human made isotope owing to atmospheric nuclear weapons tests in the 20th century and contamination from the Chernobyl disaster in 1986. You can read about the levels of 137-Cs in the North Pacific pre-Fukushima here.

More results will be published as they become available.

Looking For Fukushima Contamination in Mushrooms and Soil of Western North America

By Jay T. Cullen

@JayTCullen

Chanterelle Cantharellus cibarius
 

The purpose of this diary is to report results from a recently published, peer reviewed study (behind paywall) examining the degree of Fukushima contamination in fungi and soil of western North America. The diary is the most recent contribution to an ongoing series which aims to provide evidence from scientific studies assessing the impact of the Fukushima Daiichi disaster on the environment and the health of residents of North America. Trappe and colleagues measured the activity of cesium isotopes (134-Cs half life ~ 2 years; 137-Cs half life ~30 years) in wild mushrooms, soil and leaf litter of the west coast from California up to Vancouver Island. The conclusions of the study were as follows:

  1. No activity measurements exceeded levels thought to impact human health
  2. 137-Cs activity increased in fungi and soil towards the north
  3. 134-Cs increased to the south in leaf litter
  4. Chanterelles did not significantly bioconcentrate Cs isotopes
  5. 137-Cs and 134-Cs activities were highly variable from sample to sample
  6. 137-Cs levels largely reflected non-Fukushima sources from either atmospheric weapons tests in the last century or the Chernobyl disaster in 1986

Continue reading Looking For Fukushima Contamination in Mushrooms and Soil of Western North America