Thread: 1/ Team members of @FukushimaInFORM have been monitoring the impacts of the #Fukushima disaster on marine and public health in Canada since the meltdowns at the Daiichi nuclear power plant in 2011
2/ We have a new paper in press summarizing our work looking for #Fukushima contamination in almost 300 #Pacific salmon collected near to North America in 2013-2016 returning to the rivers shown below 
3/ Here is what we found. Pacific salmon always have a naturally occurring radioisotope in their flesh called Polonium-210. 210-Po has a half life of 138 days and is produced by the decay chain of Uranium-238. 210-Po was discovered by Marie Curie in 1898
4/ 210-Po emits alpha radiation which can be dangerous to living organisms if ingested in high enough amounts. The levels of 210-Po in the fresh fish we analyzed was found to lead to a dose of ionizing radiation per kilogram of fish consumed is 0.88 microSievert
5/ Average ionizing radiation dose to humans per year is 2400 microSv from all natural sources of radiation meaning that the dose from 210-Po in a kg of fish is less than 0.05% of a fish consumers yearly total and not a significant health risk
6/ We also measured Cesium-137 in the fish. While difficult to detect we could quantify trace levels of this isotope. Levels in #Pacific fish we studied did not increase over time and would contribute an ionizing radiation dose of 0.003 microSievert per kg consumed.
7/ This dose from human produced 137-Cs, largely present in the Pacific from nuclear weapons testing in the 1950-60s, is about 300 times less significant than the 210-Po related dose. We can conclude the following from this study
8. 1) We see no evidence of bioaccumulation of 137-Cs in Pacific salmon in waters off of North America, 2) The ionizing radiation dose from fish consumption along our coast is not a health concern. The paper will be published in Health Physics Journal. End.
