Radioactivity in mushrooms from selected locations in the Bohemian Forest, Czech Republic.

137Cs is one of the most important radionuclides released in the course of atmospheric nuclear weapon tests and during accidents in nuclear power plants such as that in Chernobyl, Ukraine, or Fukushima, Japan. The aim of this study was to compare 137Cs and 40K concentrations in particular species of mushrooms from selected locations in the Bohemian Forest (Czech: Sumava), Czech Republic, where a considerable contamination from the Chernobyl accident had been measured in 1986. Samples were collected between June and October 2014. Activities of 137Cs and 40K per dry mass were measured by means of a semiconductor gamma spectrometer. The 137Cs values measured range from below detection limit to 4300 ± 20 Bq kg-1, in the case of 40K from 910 ± 80 to 4300 ± 230 Bq kg-1. Differences were found between individual locations, due to uneven precipitation in the course of the movement of the radioactive cloud after the Chernobyl accident. There are, however, also differences between individual species of mushrooms from identical locations, which inter alia result from different characteristics of the soil and depths of mycelia. The values measured are compared with established limits and exposures from other radiation sources present in the environment. In general, it can be stated that the values measured are relatively low and the effects on the health of the population are negligible compared to other sources of ionizing radiation.

Effective Doses of Employees at the Former Uranium Processing Plant MAPE Mydlovary, Czechoslovakia.

Results are presented of a survey of almost 1000 dosimetric records of employees at the former uranium processing plant MAPE Mydlovary. Located ~20 km to the north-west of Ceské Budejovice in South Bohemia, it was the place where most of the uranium ore mined in Czechoslovakia in the years from 1962 to 1991 was processed. The records refer to incorporation of short-lived radon progeny and long-lived radionuclides as well as external gamma exposure. The average annual doses calculated from the recorded data were 2.7 ± 1.4, 5.0 ± 3.1 and 1.7 ± 0.9 mSv from these three sources, respectively. Thus, the relative contributions of these components to the effective dose were 29 ± 6, 53 ± 14 and 18 ± 13% , respectively. This is different from the findings in an earlier study for the exposure of uranium miners, where the overall doses were similar, but over 50% was contributed by short-lived radon progeny. No legal limits applicable at the time were exceeded, as the inclusion of long-lived radionuclides in the dose calculations was not yet obligatory.

Monitoring radionuclides in the atmosphere over the Czech Republic after the Fukushima Nuclear Power Plant accident.

This paper presents the results of atmospheric radioactivity monitoring over the Czech Republic, as obtained by the Radiation Monitoring Network, following the Fukushima Dai-Ichi Nuclear Power Plant accident. Maximum values for (131)I were 5.6 mBq m(-3) in aerosol form and 13 mBq m(-3) in gaseous form. The maximum values for (134)Cs and (137)Cs were 0.64 and 0.72 mBq m(-3), respectively. The estimated effective half-time for removing the activity from the atmosphere was 6-7 d and 3.5 d for caesium and iodine, respectively. The gaseous-to-total activity ratios of (131)I ranged between 0.3 and 0.9, with an arithmetic mean value of 0.77. The mean value for the (134)Cs/(137)Cs ratios was close to 1.0. The effective inhalation dose due to the accident for an adult living in the Czech Republic was estimated at <4 × 10(-5) mSv, out of which the proportion of (131)I was 88%.