Observation of radioactive fallout in Hiroshima caused by the reactor accident at Chernobyl

The reactor accident at Chernobyl has caused detectable radioactive contamination not only in Europe, but also in Japan. We have measured gamma-ray energy spectra of radioactivities in aerosol sample, rainfall, tap water and ground water in Hiroshima. On the air filter, twenty nuclides, 95Zr, 95Nb, 99Mo, 99mTc, 103Ru, 106Rh, 110mAg, 111Ag, 125Sb, 127Sb, 129Te, 129mTe, 131I, 132Te, 132I, 134Cs, 136Cs, 137Cs, 140Ba and 140La were observed. Maximum concentration of 131I in air was observed on 8 May with amount of 0.20 Bq/m3. In this paper, radioactivity measurements for two weeks were reported. Comparison of radioactive fallouts in Hiroshima with those in Europe were given, and difference of the fallouts, mainly volatile fission poroducts, from those of the nuclear test was shown. (author)