Spatial distributions and temporal changes of radioactive fallout released by the Fukushima Dai-ichi Nuclear Power Plant accident have been investigated by two campaigns with three measurement schedules. The inventories (activities per unit area) of the radionuclides deposited onto ground soil were measured using portable gamma-ray spectrometers at nearly 1000 locations (at most) per measurement campaign. Distribution maps of the inventories of (134)Cs, (137)Cs, and (110m)Ag as of March, September, and December 2012 were constructed. No apparent temporal change of the radionuclide inventories was observed from March to December 2012. Weathering effects (e.g., horizontal mobility) were not noticeable during this period. Spatial dependence in the ratios of (134)Cs/(137)Cs and (110m)Ag/(137)Cs were observed in the Tohoku and Kanto regions. The detailed maps of (134)Cs and (137)Cs as of September 2012 and December 2012 were constructed using the relationship between the air dose rate and the inventory.

Distribution maps of air dose rates around the Fukushima Dai-ichi Nuclear Power Plant were constructed using the results of measurement obtained from approximately 6500 locations (at most) per measurement period. The measurements were conducted 1 m above the ground using survey meters in flat and spatially open locations. Spatial distribution and temporal change of the air dose rate in the area were revealed by examining the resultant distribution maps. The observed reduction rate of the air dose rate over the 18 months between June 2011 and December 2012 was greater than that calculated from radioactive decay of radiocesium by 10% in relative percentage except decontaminated sites. This 10% difference in the reduction of the air dose rate can be explained by the mobility of radiocesium in the depth direction. In the region where the air dose rate was lower than 0.25 μSv h(-1) on June 2011, the reduction of the air dose rate was observed to be smaller than that of the other dose rate regions, and it was in fact smaller than the reduction rate caused by radioactive decay alone. In contrast, the reduction rate was larger in regions with higher air dose rates. In flat and spatially open locations, no significant difference in the reduction tendency of air dose rates was observed among different land use classifications (rice fields, farmland, forests, and building sites).

The hot water extract of adzuki (HWEA), which is produced as a byproduct in the adzuki bean boiling process, has anti-tumor, antioxidative, and anti-diabetic activities. In this study, we fractionated HWEA to 4 fractions using stepwise gradient column chromatography with water and ethanol, and demonstrated the effects of each fraction on antigen (Ag)-stimulated degranulation in rat basophilic leukemia RBL-2H3 cells. The 40% ethanol eluate extract (EtEx.40) showed the strongest inhibition level of these fractions. To reveal the inhibitory mechanisms underlying degranulation by EtEx.40, we investigated intracellular reactive oxygen species (ROS) production, intracellular free Ca²⁺ concentration ([Ca²⁺]i), and early intracellular signaling pathways. Treatment with EtEx.40 markedly inactivated Lyn following Ag stimulation, resulting in the suppressions of intracellular elevation of [Ca²⁺]i and production of ROS. To identify the active compound in EtEx.40, we isolated 7 flavonoids from EtEx.40 and calculated their inhibition levels on Ag-stimulated degranulation. These flavonoids inhibited degranulation by about 25-60%. We further examined the in vivo effects of HWEA or EtEx.40 using a passive cutaneous anaphylaxis (PCA) reaction. Both extracts strongly suppressed the PCA reaction. These findings suggest that HWEA and/or EtEx.40 are beneficial for alleviating type I allergic symptoms.

We assessed the repeatability and reproducibility of methods for determining low dissolved radiocesium concentrations in freshwater in Fukushima. Twenty-one laboratories pre-concentrated three of 10 L samples by five different pre-concentration methods (Prussian-blue-impregnated filter cartridges, coprecipitation with ammonium phosphomolybdate, evaporation, solid-phase extraction disks, and ion-exchange resin columns), and activity of radiocesium was measured. The z-scores for all of the 137 Cs results were within ± 2, indicating that the methods were a good degree of precision. The relative standard deviations (RSDs) indicating the reproducibility among different laboratories were larger than the RSDs indicating the repeatability in each separate laboratory.

With the aim for an analytical validation of the inductively coupled plasma mass spectrometry method by neutron activation analysis, squid (Todarodes pacificus) was collected from Japanese inshore during 1981 to 1996. The internal organs of squid collected in 1981 to 1988 were dried at 105 for overnight and ashed for 48 hours at 450 . Ashed samples were pulverized and homogenized. On the other hand, squid was collected in 1996 for the purpose of concentration factor. The squid was cautiously divided into edible, born, craw, liver, and others by using Teflon scissors and forceps. These samples were also ashed. Determination of nine elements (V, Mn, Fe, Co, Cu, Zn, Rb, Ag and Cd) in the ash and SRM 1572 citrus leaves, SRM 1577b bovine liver, and NIES No. 9 sargasso was carried out by non-destructive neutron activation analysis (INAA) at the TRIGA Mark II reactor of Rikkyo University with the flux of 5 10 11 n cm 2 s 1 . The standards were prepared by impregnating an aliquot of SPEX standard solution into filter paper. For ICP-MS, about 0.5 grams of ash samples and standard reference materials were dissolved into 7 M HNO3 and then evaporated to dryness. The residue was completely dissolved into 1 M HNO 3 and diluted with pure water. Concentration of 13 elements (V, Mn, Fe, Co, Ni, Cu, Zn, Rb, Ag, Cd, Cs, Ba and Pb) was determined after an addition of internal standard to avoid any instrumental drift. The analytical results of nine elements in squid organs by ICP-MS were agree well with INAA within 10 . Analytical results of the other four elements (Ni, Cs, Ba and Pb) were also confirmed by ICP atomic emission spectrometry, atomic absorption spectrometry and flame photometry techniques. This paper describes the usefulness of ICP-MS for trace elements in squid organs, and an application to determine the concentration factors. Particularly, Co, Zn, Ag, and Cd were concentrated into liver with concentration factors of 10 5 10 6 . The analysis of trace elements in squid organs was found to be a useful method for studying heavy metal or radioactive contamination in a marine environment.