Contamination of Japan 39 – “Canopy-Forming Kelps as California’s Coastal Dosimeter: 131I from Damaged Japanese Reactor Measured in Macrocystis pyrifera”

http://pubs.acs.org/doi/abs/10.1021/es203598r?journalCode=esthag

Steven L. Manley*† and Christopher G. Lowe†
† Department of Biological Sciences, California State University, Long Beach, California 90840 United States
Environ. Sci. Technol., Article ASAP
DOI: 10.1021/es203598r
Publication Date (Web): March 6, 2012
Copyright © 2012 American Chemical Society

Abstract.
The Fukushima Daiichi Nuclear Plant, damaged by an earthquake and tsunami on March 11, 2011 released large amounts of 131I into the atmosphere, which was assimilated into canopy blades of Macrocystis pyrifera sampled from coastal California. The specific activity calculated to the estimated date of deposition/assimilation ranged from 0.6 to 2.5 Bq gdwt–1, levels greater than those measured from kelps from Japan and Canada prior to the release. These 131I levels represent a significant input into the kelp forest ecosystem. Canopy-forming kelps are a natural coastal dosimeter that can measure the exposure of the coastal environment to 131I and perhaps other radioisotopes released from nuclear accidents. An organizational mechanism should be in place to ensure that they are sampled immediately and continuously after such releases. end quote.

Full text available at above link ($35)

The Journal Environmental Science and Technology reports in a new study that the Fukushima radiation plume contacted North America at California “with greatest exposure in central and southern California”, and that Southern California’s seaweed tested over 500% higher for radioactive iodine-131 than anywhere else in the U.S. and Canada:

Projected paths of the radioactive atmospheric plume emanating from the Fukushima reactors, best described as airborne particles or aerosols for 131I, 137Cs, and 35S, and subsequent atmospheric monitoring showed it coming in contact with the North American continent at California, with greatest exposure in central and southern California. Government monitoring sites in Anaheim (southern California) recorded peak airborne concentrations of 131I at 1.9 pCi m−3

Anaheim is where Disneyland is located.

EneNews summarizes the data:

Corona Del Mar (Highest in Southern California)

2.5 Bq/gdwt (gram dry weight)= 2,500 Bq/kg of dry seaweed

Santa Cruz (Highest in Central California)

2.0 Bq/gdwt = 2,000 Bq/kg of dry seaweed

Simon Fraser University in Canada also tested North American seaweed after Fukushima:

“In samples of dehydrated seaweed taken on March 15 near the North Vancouver SeaBus terminal, the count was zero; on March 22 it was 310 Bq per kilogram; and by March 28 it was 380 Bq/kg.” -Vancouver Sun
Seaweed in Seattle also tested positive for iodine-131; levels were not reported -KIRO
No results after March 28 were reported

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