Extended testing of select 2016 salmon samples has identified the Fukushima-fingerprint isotope in one sample re-measured earlier this year. The maximum level of contamination observed in a sample (134Cs: 0.07 Bq kg-1, 137Cs: 0.51 Bq kg-1) is over 1,700 times lower than the Health Canada Action Level (1,000 Bq kg-1) and is not known to be a health risk for either humans or the environment.
More results from InFORM’s 2016 biotic monitoring results are now available and reveal that Fukushima contamination was not detected in sampled BC salmon after initial testing. These results are an update to the earlier report on the first 20 of the 123 fish donated by First Nations from 10 rivers in British Columbia and Yukon in 2016. Nine fish did have individual levels of 137Cs detected near the minimum detectable concentration (MDC). These levels (<0.7 Bq kg-1) are not known to present a significant health risk and are ~1,400x lower than the national and international action level (1000 Bq kg-1). For perspective, you would need to consume 1000-1500 kg of salmon at this concentration of cesium to receive the same radiation dose acquired during a single cross country flight. There has not been a significant increase to the total 137Cs concentration in BC salmon since InFORM monitoring began in 2014.
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:
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
the additional dose resulting from Fukushima derived contamination is far less than the normal variation in dose from place to place in Canada
there are likely to be no health impacts related to this small, incremental dose