Woods Hole announced some recent findings of Fukushima identified radioactive contamination found offshore in the US and Canada. The test samples were collected seven months ago, with the exception of sample CS109 that remains undated. The press release provided no actual data except the undated CS109 sample, but insisted it was “trace” amounts. and “well below internationally established levels of concern to humans and marine life” but did not cite any sources for this claim.
Pacific contamination levels during 1960′s atomic bomb testing in the Pacific reached 30 bq/m3.
Various studies have indicated radiation levels off the US/Canadian Pacific coast could reach 10-30 bq/m3 after Fukushima based on early understanding of the radiation releases from Daiichi. Those ocean releases were admitted to be much longer in duration by TEPCO in late 2013 and again in 2014. There is also a wide variance in estimated total releases to the sea, making projections more complicated.
Various studies have indicated radiation levels off the US/Canadian Pacific coast could reach 10-30 bq/m3 after Fukushima based on early understanding of the radiation releases from Daiichi. Those ocean releases were admitted to be much longer in duration by TEPCO in late 2013 and again in 2014. There is also a wide variance in estimated total releases to the sea, making projections more complicated.
Combined cesium readings off the northern California coast were at 8.1 bq/m3 in August of 2014. This reading is already close to the lower end of the projected peaks of contamination. There also appears to be some difference between contamination and the depth the reading is taken at. More of the cesium 134 findings were at shallower depths. Most of these readings were also from July and August of 2014.
The phase of 2014-2015 is considered the early onset of the contamination plume reaching the US west coast. Compounding the issues with the data sets is that locations are not being testing repeatedly over the years in many cases. Locations north of Hawaii that had detected Fukushima related contamination in 2013 were not re-tested in 2014 or 2015. There is also the problem that cesium 134 has a short half life and may decay below detection while cesium 137 would continue to show increases. If cesium 134 is being used as the only “proof” of a problem, it would be an over all inaccurate assumption. Some early 2014 readings taken off the North American coastlines may prove useful if follow up testing is done later at those locations...
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