出版社：State Institution “O.M. MARZEYEV INSTITUTE FOR PUBLIC HEALTH OF THE NAMS OF UKRAINE"
摘要：The objective. To study 14C content variation in the atmosphere by measuring the specific 14C activity in the annual growth of trees for background conditions and under the effect of the nuclear-energy complex site as well as the comparison of the 14C spatial distribution around the object. Materials and methods. 14C content measurements in the annual growth (tree rings) of pine wood for 14C variation studies in the air for the time interval since the end of 40- th of the last century - the period when there have been the greatest fluctuations in radiocarbon. Research objects - annual pine wood growth. Trees for the study of background oscillations were selected in Chernigiv region and for the influence of anthropogenic emissions 14C study were selected trees near the source of emissions 14C, studied earlier. In the second case, we examined the wood material of tree that grew at a distance of about 5 km from the site, and compared the results with those obtained previously for a tree that grew at a distance of about 10 km. Measurements were carried out at 14C using a traditional method based on a liquid-scintillation counting. For this study used the charred wood annual increment, of which have been previously extracted resin material in a Soxhlet apparatus. Samples of benzene were measured using a Quantulus 1220 TM LS spectrometer made by Perkin Elmer Inc. Results. Technology used in the preparation of baseline studies of samples allows to obtain results similar to the direct measurements of 14C in the air. Studies of samples taken in the area of nuclear facility influence showed the results concerted with previous studies of the impact of the object. Comparing the relevant research showed that the samples of the annual increment in some years have significant differences, confirmed by repeated studies. The differences can be explained by inappropriate spatial distribution at close distances from the object. Overall consistency of the data sets suggests that the earlier estimate of annual emissions and 14C emissions for the time of work does not require the re-evaluation.
