Discovery of radioactive silver (^110mAg) in spiders and other fauna in the terrestrial environment after the meltdown of Fukushima Dai-ichi nuclear power plant

Abstract

Six months after the explosion of TEPCO’s Fukushima Dai-ichi nuclear power plant, radioactive silver (110mAg), was detected in concentrations of 3754 Bq/kg in Nephila clavata (the orb-web spider; Joro-gumo in Japanese) collected at Nimaibashi, Iitate village in Fukushima Prefecture, whereas 110mAg in the soil was 43.1 Bq/kg. A survey of 35 faunal species in the terrestrial environment during the 3.5 years after the accident showed that most of Anthropoda had two orders higher 110mAg in their tissues than soils, although silver is not an essential element for their life. However, tracing of the activity of 110mAg detected in spider Atypus karschi collected regularly at a fixed location showed that it declined much faster than the physical half-life. These results suggest that 110mAg was at once biologically concentrated by faunal species, especially Arthropoda, through food chain. The factors affecting the subsequent rapid decline of 110mAg concentration in faunal species are discussed.

Pollution of radiocesium and radiosilver in wharf roach (Ligia sp.) by the Fukushima Dai-ichi Nuclear Power Plant accident

“…1 and Table 2). The 10m Ag concentration in our specimens were comparable to those observed in zooplankton, crabs, and shrimp collected from areas near our sampling sites [14,36,37]. The 110m Ag concentration increased with decreasing distance from the FDNPP (Fig.…”

Decline in intertidal biota after the 2011 Great East Japan Earthquake and Tsunami and the Fukushima nuclear disaster: field observations

“…The 110m Ag: 137 Cs ratios in the limpet and rock shell were 1.5–54.2 and 13.6–15.7, respectively; the respective 110m Ag: 134 Cs ratios were 2.1–64.0 and 16.4–20.9 ( Supplementary Table S3 ). The 110m Ag: 137 Cs ratios in the limpet and rock shell were generally higher than those in terrestrial and freshwater organisms in Fukushima Prefecture such as spiders, ants, earthworms, frogs, and lizards, as well as those in freshwater crabs and snails 18 . Further study is needed to explain these phenomena, because the transport mechanisms and fate of radio-silver and radio-caesium might differ among terrestrial, freshwater and marine environments.…”

Absence of Detectable Radionuclides in Breast Milk in Sendai, Japan in 2012 Even by High-Sensitivity Determination: Estimated Dose among Infants after the Fukushima Nuclear Disaster

“…131 I was not expected to be detected from breast milk samples, as it has a short half-life and was only detected at the early stage of the accident [ 8 ], and therefore focused on radiocesium and 40 K to estimate radionuclide intake and dose. It is reasonable to suppose that the contribution of 110m Ag would be negligible, as the quantities released by the accident were smaller than those of 137 Cs and as 110m Ag is not bioaccumulative in food products other than mollusks and arthropods [ 20 ]. Table 2 shows the distribution of radionuclide levels.…”