[en] Radionuclide releases together with escaping fly ashes (from 45x10⁶ kg in previous decades to 8x10⁶ kg annually in 1996) from the main local and several small coal-fired power plants resulted in a relatively small increase in natural radioactivity levels in the Lodz region. The natural gamma terrestrial radiation dose rates (1 m above ground level) were measured at 82 points including in the vicinity of power plants, in the center of the town and on edge of the town. The average dose rate value for the first area was 36±1.2 nGy h^-1, whereas the same dose rate for the edge of town was slightly lower 30±0.9 nGy h^-1, but this difference was statistically significant. Further confirmation of the technologically slightly enhanced exposure of the local population to natural radionuclides was achieved by γ-spectrometry measurement of the uranium and thorium decay series radionuclides in the surface soil profiles (up to 30 cm depth). The average increase of ²²⁶Ra and ²³²Th radionuclides in the top layer of soil (0-10 cm) according to the 20±30 cm depth layer was 21% and 17%, respectively. However, due to the relatively low levels of ²³²Th (14.3 Bq kg^-1) and ²³⁸U (16.8 Bq kg^-1) in this area, the annual average effective dose from the natural terrestrial radiation for the local population is also relatively low, 0.28 mSv only

[en] The radionuclide releases together with escaping fly ashes (ca. 3x10⁶ kg annually) and the deposited bottom slags from three local coal fired power plants resulted in the enhanced natural radioactivity levels in this region. The annual emissions of the most important radionuclides to the atmosphere from that sources were; 1.2 Gbq for ²¹⁰Pb, 1.1 GBq for ²³⁸U, 0.8 GBq for ²²⁶Ra, 0.6 Gbq for ²³²Th and 5.3 GBq for ⁴⁰K. Two areas with expected higher values of the solid fall out were found inside the town by computer modeling. Natural γ background dose rates (1 m above ground levels) were measured using thermoluminescence detectors at over 80 points including those areas. The average dose rate value for Lodz town was equal 34 nGy/h , whereas for those two areas was slightly higher (38 nGy/h). Further confirmation of the technologically enhanced exposure of local population to natural radionuclides was achieved by γ-spectrometry measurements of the surface soil profiles (up to 30 cm depth). However, due to the low level of the natural radionuclides in surface soil in Lodz region the average effective dose for the local population from terrestrial γ radiation is relatively small - only 0.28 mSv per year. The wide scale survey of indoor radon concentration (626 dwellings) showed that the use of fly ashes in buildings materials has a negligible effect on the indoor radon levels. The measurements resulted in a average Rn concentration of 21.4 Bqxm^-3 and a median value of 15.1 Bqxm^-3. Analysis of the data indicates that most indoor radon comes from the underlying soil, which contains relatively little ²²⁶Ra (10-20 Bqxkg^-1). The corresponding annual effective dose for the local population equal to 0.54 mSv from this source can be appraised. (author)

No abstract available

No abstract available

[en] Soil samples were collected at three fly ash dumping sites in Poland to monitor the concentration of natural radionuclides and ¹³⁷Cs. The resulting values are presented for all three sites. (A.K.)

[en] The activity levels of some natural radionuclides and ¹³⁷Cs in the surface soil layer (0-5 cm) within and outside three recultivated coal fly ash disposal sites have been determined by (γ-ray spectrometry with an REGe detector. The activity of natural radionuclides from the ²³⁸U and ²³²Th series in the soil samples ranged from 7.5 to 77 Bq/kg. No significant differences in the activity of concentrations within and outside of two of the disposal sites have been found. However, in the vicinity of one site an abnormally high depositional flux of ²¹⁰Pb was observed. This can be explained as a result of the high ²²²Rn emanation from deposited fly ash covered with an insufficient layer of soil. The observed correlation between an excess of ²¹⁰Pb and the concentration of anthropogenic radionuclide ¹³⁷Cs in surface soil confirms the fact, that local geographic conditions can substantially influence the radionuclide depositional flux from the atmosphere to the soil