Forest fires are of special interest for Belarus because of radioactive contamination caused by the 1986 accident at the Chernobyl Nuclear Power Plant. This work aims to determine the potential activity of long-lived radionuclides in surface air caused by forest fires and to estimate the potential health threat to firefighters. The methodology is based on measurements of radioactivity released by forest fuel materials using a combustion chamber. The emissions were combined with a simple dispersion model to estimate air concentrations and dose to firefighters. The inhalation dose from transuranium elements tend to be an order of magnitude greater than that from Cesium-137. Although there was variability among sites, about half of the total dose was caused by external radiation, as measured by dosimeters. Overall effective radiation dose ranged from 3 to 7 uSv for a 1-h exposure, far below the annual effective dose of 20 mSv for workers and 1 mSv for the public. Although, the risk of exceeding annual effective dose limits is low during small fires, such data are important to inform the population and reduce social and psychological stress caused by popular sources.

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An important component of forest firefighting strategies is related to the accurate prediction of fire risks. This article describes the development process of special decision support system (ForestFire GIS) - for the analysis of climatic conditions and definition of fire risks in Belarus including radioactively contaminated territory. The application consists of two basic modules: fire danger rating module and module of radionuclides transfer during the fire event. Fire danger rating module uses data on daily temperature, dew point and 24-hour rainfall to calculate weather based fire hazard index (FHI). The program provides recommendations for firefighting officials about efficient wildfires suppression strategy. GIS core (based on the MapWinGIS) performs all basic operations with map layers (scaling, moving, geocoding etc.), load and save changes. The ForestFire GIS was tested for the beginning of fire seasons in Gomel region in Belarus.

137 Cs and 40 K uptake by vegetable plants was examined in a number of places in Belarus located at the outer perimeter of the 30-km Chernobyl zone. Differences in the uptake of 40 K and 137 Cs by plant species were not found to be related to the radionuclide content in the soil, but are essentially related to plant features. Vegetable plants were found to accumulate 40 K more actively than 137 Cs. For 40 K and 137 Cs, the ratio of the nuclide content in plants to their content in soil shows a tendency to decrease with increasing nuclide concentration in soil.

The radioactive environmental contamination caused by Chernobyl accident, stimulated working out of a problem of radiation protection biota. At the present investigation the following reactions of plants to irradiation have been chosen: germination of seeds, a state of mitotic cells of roots, phototaxis of chloroplasts and parity of chlorophyll forms in vivo. The research object was barley. The doses of irradiation were 2.5 and 5.0 Gy. According to the results, indicators of germination of seeds obtained for the irradiated and not irradiated objects have been appeared almost identical (∼94 %). The analysis of cells of roots has revealed acceleration of rates of cell fission at the irradiated plants in comparison with not irradiated plants. The dependences of damage cells and of exit of aberration cells from irradiation dose were observed. Phototaxis of chloroplast was estimated for 7-day sprouts. Phototaxis (moving chloroplast under the influence of light) -the normal physiological process occurring in cells of leaves. At the present study the decrease negative and positive phototaxis at the irradiated plants has been established. Dependence between decrease in intensity of this process and an irradiation dose is observed. Positive phototaxis has decreased in 1.4 and 1.8 times, accordingly at an irradiation in a dose 2.5 and 5.0 Gy, negative -in 1.2 and 1.7 times, respectively. The definition of the maintenance of chlorophyll forms (range of 650-715 nm) in the 1st leave of the 8-and 11-days sprouts of the barley which has grown from seeds irradiated in dose 4, 0 Gy. Changes of percentage of four forms at 8-days and two forms at 11-days plants were established. At 8-days sprouts the increase in a share of spectral forms of 671 and 683 nm on 7.5 and 14.1 %, accordingly, and decrease in forms of 686 and 693 nm on 14.5 and 7.1 % was observed. In case of 11-days sprouts the distinction in the maintenance of spectral forms of 671 and 693 nm smooth out, for the form of 683 nm practically remain (12.9 %) and for the form of 686 nm increase to 58.6 %. The presented results together with future data for smaller doses can used to obtain the dose-effect relationship. 208