Fukushima-derived radionuclides in the ocean and biota off Japan.
Proc Natl Acad Sci U S A
; 109(16): 5984-8, 2012 Apr 17.
Article
em En
| MEDLINE
| ID: mdl-22474387
ABSTRACT
The Tohoku earthquake and tsunami of March 11, 2011, resulted in unprecedented radioactivity releases from the Fukushima Dai-ichi nuclear power plants to the Northwest Pacific Ocean. Results are presented here from an international study of radionuclide contaminants in surface and subsurface waters, as well as in zooplankton and fish, off Japan in June 2011. A major finding is detection of Fukushima-derived (134)Cs and (137)Cs throughout waters 30-600 km offshore, with the highest activities associated with near-shore eddies and the Kuroshio Current acting as a southern boundary for transport. Fukushima-derived Cs isotopes were also detected in zooplankton and mesopelagic fish, and unique to this study we also find (110 m)Ag in zooplankton. Vertical profiles are used to calculate a total inventory of ~2 PBq (137)Cs in an ocean area of 150,000 km(2). Our results can only be understood in the context of our drifter data and an oceanographic model that shows rapid advection of contaminants further out in the Pacific. Importantly, our data are consistent with higher estimates of the magnitude of Fukushima fallout and direct releases [Stohl et al. (2011) Atmos Chem Phys Discuss 1128319-28394; Bailly du Bois et al. (2011) J Environ Radioact, 10.1016/j.jenvrad.2011.11.015]. We address risks to public health and marine biota by showing that though Cs isotopes are elevated 10-1,000× over prior levels in waters off Japan, radiation risks due to these radionuclides are below those generally considered harmful to marine animals and human consumers, and even below those from naturally occurring radionuclides.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Cinza Radioativa
/
Radioisótopos
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Poluentes Radioativos da Água
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Biota
Tipo de estudo:
Prognostic_studies
Limite:
Animals
/
Humans
País como assunto:
Asia
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article