Tag Archives: Fish

No Fukushima Contamination in 2015 Alaskan Fish

Alaska Department of Environmental ConservationThe Seattle Times is reporting no contamination in any of the 24 Alaskan salmon, halibut, pollock,  cod, or sablefish that were sampled from 4 different regions in 2015 for the Alaskan Department of Environmental Conservation.

Read the full article.

See the results from the Department of Environmental Conservation.

Presently, InFORM members at Health Canada are running the ~160 salmon samples from over 15 different major BC fisheries collected in 2015 and we will report the results as soon as they become available.

Radioactive Strontium and Cesium in Fish From the Harbor at the Fukushima Dai-ichi Nuclear Plant

By Jay T. Cullen

The purpose of this post is to report on a recent peer-reviewed study that investigated the radionuclide content of fish caught in the harbor of the Fukushima Dai-ichi Nuclear Powerplant (FDNPP) in 2012 and 2013. The post is also written in part to address questions like:

Why don’t you measure 90Sr in fish you catch off of North America?

This post is part of an ongoing series dedicated to summarizing results from scientific research into the impact of the FDNPP disaster on the environment. Fujimoto and colleagues measured the activity of Cesium-134 (134Cs half life ~2 years), Cesium-137 (137Cs half life ~30 years) and Strontium-90 (90Sr half life ~29 years) in fish collected from the FDNPP harbor and just outside the port in 2012 and 2013. Fish were most contaminated in the harbor and had radiocesium activity concentrations (in whole body without internal organs, Bq kg-1 – wet weight) that were ~200-330 times higher than measured 90Sr levels. The much lower 90Sr levels compared to radiocesium in the fish is consistent with much lower releases of 90Sr to the Pacific Ocean compared to radiocesium in the aftermath of the meltdowns at FDNPP (see here, here and here for example). The activity of radiocesium in fish diminishes dramatically with distance from the harbor and as of April-June 2015 none of the fish caught in Fukushima prefecture waters exceeded the stringent 100 Bq kg-1 Japanese safety standard. Across the Pacific, we have yet to detect Fukushima derived radiocesium in salmon and steelhead trout caught in British Columbian waters as part of the Fukushima InFORM monitoring effort. 90Sr is much more difficult and costly to analyze in environmental samples than are the cesium isotopes. The results of the Fujimoto study suggest that 90Sr from Fukushima is unlikely to be found at detectable levels in marine organisms in the northeast Pacific and that resources to monitor the impact of the disaster on our marine environment should focus on the detection of the cesium isotopes. Continue reading Radioactive Strontium and Cesium in Fish From the Harbor at the Fukushima Dai-ichi Nuclear Plant

Update: Monitoring Results For Sockeye Salmon and Steelhead Trout Collected Summer 2014

Summary of the amount of radioactive cesium isotopes in sockeye salmon and steel head trout harvested from BC waters in 2014 (Figure by Jonathan Kellogg jkellogg@uvic.ca).
Summary of the amount of radioactive cesium isotopes in sockeye salmon and steel head trout harvested from BC waters in 2014 (Figure by Jonathan Kellogg jkellogg@uvic.ca).

The measurements undertaken as part of the InFORM project to look for Fukushima derived radionculides in fish during our first of three years of monitoring are now complete. Sockeye salmon (Oncorhynchus nerka) and Steelhead Trout (Oncorhynchus mykiss) (as well as some Chinook, Chum and Pink Salmon) were caught off the west coast of Canada in Summer 2014 as they were returning to 9 different streams and rivers up and down the coast of British Columbia Canada. These results add to the first 19 fish which we reported on in December of 2014.

Continue reading Update: Monitoring Results For Sockeye Salmon and Steelhead Trout Collected Summer 2014

Health Canada/InFORM Analyses of the Radioactive Content of Fish Samples from Canada’s West Coast

This page mirrors information on the radionuclide content of fish measured by Health Canada and the InFORM project that can be found at Open Government, Open Data.

Continue reading Health Canada/InFORM Analyses of the Radioactive Content of Fish Samples from Canada’s West Coast

Fukushima Radionuclides in Pacific: Doses to Japanese and World Public Unlikely to Cause Health Damage

By Jay T. Cullen

The purpose of this post is to summarize a the most recent, peer reviewed scientific study to examine the likely impact of Fukushima contamination of the North Pacific on human health. The blog is part of a continuing series that seeks to communicate the results of scientific studies aimed at determining the impact of the triple meltdowns at the Fukushima Dai-ichi nuclear power plant (FDNPP) on ecosystem and public health. Povinec and Hirose’s recent paper in Scientific Reports examined the variation in Fukushima derived 90-Strontium (90Sr half life 28.8 years), 134-Cesium (134Cs half life ~2 years) and 137-Cesium (137Cs half life ~30 years) in seawater and biota offshore of the FDNPP and in the northwest Pacific. These isotopes are most likely to represent radiologically health risks to consumers of Pacific seafood given their propensity to concentrate in organisms and, in the case of 90Sr and 137Cs, their longevity in the environment. Doses to the Japanese and world population were estimated and compared to doses attributable to naturally occurring isotopes present in food. Doses from food caught in coastal waters right next to the FDNPP to 20 km offshore were similar to doses from naturally occurring isotopes (primarily 210Po) while doses from the consumption off fish caught in the open northwest Pacific were much lower than natural doses. In each case the individual doses are well below levels where any negative health effects would be measurable in Japan or elsewhere. Continue reading Fukushima Radionuclides in Pacific: Doses to Japanese and World Public Unlikely to Cause Health Damage