[Effects of chronic irradiation of Scots pine (Pinus sylvestris L.) in Chernobyl exclusion zone].

The quantitative "dose rate-effect" dependences are presented for the cytogenetic damages in the seedlings and apical meristem of Scots pine growing in the Chernobyl zone. The specific patterns of dynamics of formation of the morphological effects in the studied species are considered for the conditions of the internal and external chronic irradiation. The correlation dependencies are established for the irradiation effects appearing at the morphological and cell level. The assumption concerning the mechanism of the morphological changes formation is done.

[Dose dependence of the frequency of morphological changes in Scots pine (Pinus sylvestris L.) in Chernobyl exclusion zone].

Patterns and main parameters of the dynamics of radioactive contamination of organs of Scots pine in the plantations of Chernobyl zone are presented. On the basis of this data and within the frameworks of the microdosimetric approach, the dosimetric model for the apical meristem of the pine trees was created. The dose rates were calculated for the trees of the experimental array growing at three sites in the exclusion zone and one outside, which differed by three orders of magnitude of the trees' radioactive contamination levels. Comparable high, up to several Gy/y, levels of the dose rate of chronic irradiation were shown for the plantation at the Red Forest site. Such an expressed radiation factor results in a high frequency of the morphological changes at this site. The dose rate-effect dependence was formulated for this type of the radiobiological effects.

[Radio-ecological and hygienic assessment of consequences of forest fires in the areas polluted during the Chernobyl accident]. / Radioékologicheskaia i gigienicheskaia otsenka posledstvii lesnykh pozharov na territorii, zagriaznennoi v rezul'tate Chernobyl'skoi avarii.

Retransfer of radionuclides on the condensation trails of Chernobyl radioactive fallouts during forest fires has been experimentally evaluated and their mathematical transfer model verified. It has been shown that radionuclide retransfer will make no great impact on additional pollution of an area even under the most unfavourable conditions. The contribution of convective and non-convective components of transfer to the formation of a radioactive aerosol concentration field has been assessed. Time course of changes in the concentration of radioactive aerosol and its dispersive composition are shown in different phases of fire and at different distance from its source.

[Behavior of fuel hot particles in the body of cows at oral intake]. / Povedenie toplivnykh goriachikh chastits v organizme korov pri peroral'nom postuplenii.

It was studied the behaviour of fuel hot particles (analogous to Chernobyl) in gastrointestinal tract of cows. The values of caesium and strontium radionuclides transfer to the cows organism and its transition parameters to milk after the single per oral intake to the organism of animals are estimated. It is shown, that the biological simplicity of radionuclides in the fuel hot particles at two parameters lower, than the same radionuclides in washed phases.

[Radionuclide inhalation during agricultural work in the regions polluted by the Chernobyl accident]. / Ingaliatsionnoe postuplenie radionuklidov pri selskokhoziaistvennykh rabotakh na territoriiakh, zagriaznennykh v rezultate Chernobylskoi avarii.

With pollution of agricultural fields by plutonium at a level of more than 3.7 kBg/m2 and cesium more than 7.4 MBq/m2 radionuclide levels in tractor cabin can exceed the permissible level. However field work being seasonal, annual level of inhaled radionuclides does not exceed the permissible limit. Actually the equivalent dose for the lungs does not exceed just few mSv under conditions of agricultural production.