Fukushima radiation monitoring is indicating that concentrations may be slightly decreasing from their peak in January 2018. Levels remain well below those known to be a considerable ecological and health risk, according to the latest monitoring data. The new data, collected between December 2018 and February 2019 (posted in the map above), are from samples collected through our citizen science monitoring network in sixteen coastal communities from Victoria to Lax Kw’alaams.
In 2018, 40 salmon were sampled from hatcheries and donated from our First Nations partners around BC and Yukon. No Fukushima radiation (cesium-134) was detected in any of the samples and there were no individual fish with detectable levels of either cesium-134 or cesium-137. Through a technique to increase the detection sensitivity that involves adding the data from multiple samples we were able to determine that trace levels (~0.3 Bq m-3) of cesium-137 (that has a 30 year half-life and is present in the environment from both Fukushima and atmospheric weapons testing) were present in some salmon species.
Farther up the food chain, a sixgill shark washed ashore near Victoria in early 2019 and was also tested for Fukushima radiation. While no cesium-134 was detected, cesium-137 was detected at the 1.7 Bq m-3 level. While this is elevated when compared to the salmon tested, it is still well below any food safety threshold (1,000 Bq kg-1 as set by Health Canada).
Data from June 2018 research cruises show that the highest concentrations of the Fukushima contamination plume remain offshore. Peak concentrations of 5.1 Bq m-3 were measured along Line P nearly 300 km due west of Vancouver. These concentrations are one and a half times what was concurrently measured in coastal waters. Further out, towards Station Papa at 50 N 145 W, concentrations are lower which indicates the the center of the Alaska Gyre and outside of the main flow from the North Pacific Current. Based on a comparison of the peak concentrations sampled along Line P between August 2015 (9.3 Bq m-3), August 2016 (6.3 Bq m-3), August 2017 (4.9 Bq m-3), and now June 2018 (5.1 Bq m-3) we see a decreasing trend. This trend indicates that peak signal from the Fukushima plume as has passed through Line P and further observations are resolving the back side of the plume and/or possibly recirculation from the Alaska Gyre. Read more ->
Interested in older samples? Check out our archive!