Atomic Bomb Fallout and “Black rain” at Manose District (Hirama-cho) Located Northeast of Nagasaki City

Plutonium atomic bomb (A-bomb) was exploded at 503 meters height above Nagasaki City on August 9, 1945. Many studies on radioactive contamination, radiation dose, effect to people and so on have been conducted until now. Local fallout from the A-bomb mainly spread a lot in the east direction centering on Nishiyama area located about 4 km east of the hypocenter. Like the Hiroshima A-bomb, black rain accompanied by radioactive materials fell shortly after the explosion, but relationship between local fallout fall zone and black rain fall area has not been sufficiently elucidated, which has enhanced the concerns on radiation exposure to the A-bomb survivor. Concerning the black rain due to the Nagasaki A-bomb, it has been said that black rain did not fall across a wide area in a comprehensive way, except for the heavily contaminated Nishiyama area, but fell at various areas with conditions of light rain and/or soaking after the explosion. Among many villages or towns, especially in the Manose District where is a small intermountain village about 7.5 km northeast of the hypocenter, it had always been heard and known that the residents living there encountered black rain and experienced hair loss. In this district, the hair loss of inhabitants occurred actually with high probability, but its reason has not been elucidated well. Therefore, in order to reevaluate the local fallout level in the Manose District by the A-bomb, residual long-lived radionuclides 137Cs and Pu isotopes were measured for soil samples collected at the Manose District including the surrounding areas in July, 2011. As a result, accumulated levels of 137Cs and 239,240Pu in the Manose District were not so high, each being nearly background (BG) level. The dispersion of local fallout Pu from the A-bomb was reconfirmed by 240Pu/239Pu atomic ratios measured in soil samples at the same time, and was found to be primarily limited in the east direction, especially around the Nishiyama area. Those results were consistent with results obtained so far. Further researches are needed for understanding scientifically the cause of the high incidence rate of hair loss in this district.This research was supported by JSPS KAKENHI Grants Numbers 23406002 (April 2011-March 2014) and 26257501 (April 2014-March 2018)

What parameters affect left ventricular diastolic flow propagation velocity? in vitro studies using color m-mode doppler echocardiography

BACKGROUND: Insufficient data describe the relationship of hemodynamic parameters to left ventricular (LV) diastolic flow propagation velocity (Vp) measured using color M-mode Doppler echocardiography. METHODS: An in vitro LV model used to simulate LV diastolic inflow with Vp measured under conditions of varying: 1) Stroke volume, 2) heart rate (HR), 3) LV volume, 4) LV compliance, and 5) transmitral flow (TMF) waveforms (Type 1: constant low diastasis flow and Type 2: no diastasis flow). RESULTS: Univariate analysis revealed excellent correlations of Vp with stroke volume (r = 0.98), LV compliance (r = 0.94), and HR with Type 1 TMF (r = 0.97). However, with Type 2 TMF, HR was not associated with Vp. LV volume was not related to Vp under low compliance, but inversely related to Vp under high compliance conditions (r = -0.56). CONCLUSION: These in vitro findings may help elucidate the relationship of hemodynamic parameters to early diastolic LV filling

Ingestion of radioactively contaminated diets for two generations in the pale grass blue butterfly

Background: The release of radioactive materials due to the Fukushima nuclear accident has raised concern regarding the biological impacts of ingesting radioactively contaminated diets on organisms. We previously performed an internal exposure experiment in which contaminated leaves collected from polluted areas were fed to larvae of the pale grass blue butterfly, Zizeeria maha, from Okinawa, which is one of the least polluted localities in Japan. Using the same experimental system, in the present study, we further examined the effects of low-level-contaminated diets on this butterfly. Leaves were collected from two localities in Tohoku (Motomiya (161 Bq/kg) and Koriyama (117 Bq/kg)); two in Kanto (Kashiwa (47.6 Bq/kg) and Musashino (6.4 Bq/kg)); one in Tokai (Atami (2.5 Bq/kg)); and from Okinawa (0.2 Bq/kg). In addition to the effects on the first generation, we examined the possible transgenerational effects of the diets on the next generation.Results: In the first generation, the Tohoku groups showed higher rates of mortality and abnormalities and a smaller forewing size than the Okinawa group. The mortality rates were largely dependent on the ingested dose of caesium. The survival rates of the Kanto-Tokai groups were greater than 80%, but the rates in the Tohoku groups were much lower. In the next generation, the survival rates in the Tohoku groups were below 20%, whereas those of the Okinawa groups were above 70%. The survival rates in the second generation were independent of the locality of the leaves ingested by the first generation, indicating that the diet in the second generation was the determinant of their survival. Moreover, a smaller forewing size was observed in the Tohoku groups in the second generation. However, the forewing size was inversely correlated with the cumulative caesium dose ingested throughout the first and second generations, indicating that the diet in the first generation also influenced the forewing size of the second generation.Conclusions: Biological effects are detectable under a low ingested dose of radioactivity from a contaminated diet. The effects are transgenerational but can be overcome by ingesting a non-contaminated diet, suggesting that at least some of the observed effects are attributable to non-genetic physiological changes

Radioacitivity of the aerosol collected in Nagasaki City due to the Fukushima Daiichi Nuclear Power Plant Accident

Radioactivity of 134Cs and 137Cs was detected in the aerosol collected in Nagasaki prefectural forest park "Nagasaki Kenmin No Mori" about 20 km north-west from central Nagasaki City from Mar. 23 to Jul. 27, 2011. The highest concentrations of the nuclides were detected in the sample collected from Apr. 6 to Apr. 13 and 110mAg was also detected in the sample. The wind of Apr. 6 in the park was found to come via Fukushima with back-trajectory analysis in the web-site of National Oceanic Atmospheric Administration (NOAA), United States Department of Commerce. The concentrations in the air of 134Cs, 137Cs and 110mAg evaluated were as small as 0.47, 0.52 and 0.0054 mBq/m3 respectively. However, the concentrations of them in the collected aerosol were as large as 11.3, 12.4 and 0.12 kBq/kg, and equivalent to the level of surface soil of 5 cm in Warabidaira Iitate Fukushima, highly contaminated area. It indicates that air filters in air-conditioning facilities should be handled carefully also at Nagasaki about 1,000 km apart from Fukushima Daiichi Nuclear Power Plant. In addition, the concentration of natural radioactivity Pb-210 was found as large as 19.9 kBq/kg. Therefore, it was ascertained that the risk of air filters was already existed before the accident and the radioactivity arisen from the accident increased the risk

Effect of Static Magnetic Field on the Induction of Chromosome Aberrations by 4.9 MeV Protons and 23 MeV Alpha Particles

The effect of static magnetic field applied during in vitro exposure to 4.9 MeV protons and 23 MeV alpha particles on the induction of chromosome aberrations in human peripheral blood lymphocytes was studied. The mean frequency of dicentrics in cells irradiated in magnetic field of a magnitude about one Tesla tended to be higher than that irradiated in the absence of magnetic field for both protons and alpha particles, and the analysis of dose-effect relationships indicated that for protons the magnetic field significantly affected the dose-effect relationship. The intercellular distribution of chromosome aberrations, one of the measures of radiation quality, was not significantly influenced by the magnetic field