QUALITY OF HELIANTHUS ANNUUS HONEY OBTAINED IN THE CONDITIONS OF RADIOACTIVE CONTAMINATION

Natural honey is a source of vital amino acids, easily digestible carbohydrates, macro, microelements, biologically active substances that determine nutritional, antibacterial and antioxidant properties. In the conditions of man-caused pollution of Polissya of Ukraine due to the accident at the Chernobyl nuclear power plant, systematic control of the quality and safety of beekeeping products is important. To conduct such research, we created a group of twelve bee families - analogs of the Ukrainian breed, medium strength. Families were kept in unified multifunctional hives. At the beginning of the honey harvest, the bee families were transported to the sunflower fields, where they stayed during the blossoming of the plants. The density of radioactive contamination of 137Cs soils where sunflower was grown was 47.0 kBq / m2. We used organoleptic, physicochemical, microscopic, microbiological, and radiological methods in the study. According to standard methods, we studied the species composition of pollen grains, physicochemical parameters of centrifugal, honeycomb, and «zabrus» sunflower honey.(zabrus honey was obtained from wax caps, which we cut with an apiary knife from honeycombs filled with nectar and sealed by bees). The content of lead (Pb) in honey from sunflower obtained in the conditions of Polissya is 1.8 - 2.1 times higher than the State sanitary norms. The largest amount of it is in the centrifugal honey. In acceptable amounts, the heavy metals cadmium (Cd), arsenic (As), and 137Cs were present in honey. Pesticides, dichlorodiphenyltrichloromethylmethane, and hexachlorane were not detected in the samples. We investigated the bactericidal action against bacterial growth of typical cultures of Proteus vulgaris, Escherichia coli, Klebsiella pneumonia, Salmonella Typhimurium, and Staphylococcus aureus. Zubrus sunflower honey showed the highest antimicrobial and antioxidant properties. We found that the value of antioxidant activity (AOA) of sunflower honey depends on the method of its production, duration of storage, and solutions of extracts (alcohol, aqueous) used in research. Laboratory control of transgenic organisms in flowers and sunflower pollen did not reveal the target sequences of the cauliflower mosaic virus (CaMV) 35S promoter and the NOS terminator (nopaline synthase) of the plasmid Agrobacterium tumefaciens.

Safety of livestock products of bulls on various diets during fattening in the conditions of radioactive contamination

Production of high-quality and safe food products in the conditions of technogenic environmental pollution is a problem worldwide, especially in Ukraine. As a result of the disaster at the Chornobyl Atomic Power Plant, radioactive substances, including caesium-137, contaminated the soil not only in Ukraine, but in many other countries. Zhytomyr Oblast is the fifth largest oblast in Ukraine and one of the regions that were the most damaged by the accident. Furthermore, this territory is contaminated by the most toxic heavy metals – lead (Pb) and cadmium (Cd) that actively migrate in the biological system: soil→ plant → animal → production → human, intensely accumulating in the products of plant and animal origin. The complex ecological situation and broad spectrum of biological and toxic actions of 137Cs, Pb, Cd require a number of measures that would prevent transformation of radioactive elements and heavy metals in the organism of animals, increase animals` productivity and safety of the food products made in the conditions of the Ukrainian Polisia. Therefore, we aimed at substantiating the practicability of using silage-concentrate, silage-concentrate-root vegetable and silage-concentrate-hay types of diet for young cattle during fattening and determining the impact of accumulation of 137Сs, Pb and Cd in livestock products. To perform the studies, we formed three groups of young bulls of Ukrainian Black Pied cattle using the method of analogues with creating comfortable maintenance condition and organization of in-detail planned feeding. The diet was composed of fodders prepared in the conditions of radioactive contamination. The laboratory surveys indicated that the main sources of 137Cs ingress in the organism of the animals were roughages and various types of silages, and the sources of heavy metals Pb and Cd were hay of red clover and concentrated fodders. In the experimental studies, we determined absolute and average daily weight gains, expenditures of metabolic energy per 1 kg of weight increment, specific activity of 137Сs and concentrations of the heavy metals (Pb and Cd) in the biological system “fodder-animal-production” during feeding of bulls with various-type diets in the conditions of the III zone of radioactive pollution. It was confirmed that substituting maize silage and carbohydrate fodders increased the average daily gains in the live weight by 2.3–4.6%, decreased specific activity of 137Cs by 8.7–20.1%, the content of Pb by 36.2%, Cd by 34.1–66.7% in the longissimus at silage-concentrate-root vegetable and silage-concentrate-hay types of diet for bulls. Thus, use of silage-concentrate-root vegetable and silage-concentrate-hay types of diets compared with silage-concentrate feeding had a positive effect on their productivity and safety of the food production.

The State Scientific Automated Medical Registry, Kazakhstan: an important resource for low-dose radiation health research

Direct quantitative assessment of health risks following exposure to ionizing radiation is based on findings from epidemiological studies. Populations affected by nuclear bomb testing are among those that allow such assessment. The population living around the former Soviet Union's Semipalatinsk nuclear test site is one of the largest human cohorts exposed to radiation from nuclear weapons tests. Following research that started in the 1960s, a registry that contains information on more than 300,000 individuals residing in the areas neighboring to the test site was established. Four nuclear weapons tests, conducted from 1949 to 1956, resulted in non-negligible radiation exposures to the public, corresponding up to approximately 300 mGy external dose. The registry contains relevant information about those who lived at the time of the testing as well as about their offspring, including biological material. An international group of scientists worked together within the research project SEMI-NUC funded by the European Union, and concluded that the registry provides a novel, mostly unexplored, and valuable resource for the assessment of the population risks associated with environmental radiation exposure. Suggestions for future studies and pathways on how to use the best dose assessment strategies have also been described in the project. Moreover, the registry could be used for research on other relevant public health topics.

[RESEARCH OF INTESTINAL MICROFLORA IN THE RATS FOLLOWING THE INTERNAL AND EXTERNAL IRRADIATION]

The aim of the research was comparative investigation of the quantitative and qualitative composition of large intestinal microflora following internal (by dispersed powdered 56Mn) and internal exposure of Wistar rats. Ten weeks-old male Wistar rats were used. Rats were divided into four groups: L-56Mn group with 12 rats, H-56Mn with ten rats, 60Co group with nine rats and control group with nine rats. L-56Mn and H-56Mn groups were exposed to two different doses of 56MnO2 powder. 60Co group received 2 Gy of external 60Co γ-ray whole body irradiation. Totally 40 rats. Three rats from each group were sacrificed throw 6 hours and on days 3, 14, and 60 after the exposure. Animals were examined throw 6 hours and on days 3, 14 and 60 after exposure. Although the absorbed doses in large intestine were only 0.69 and 1.90 Gy in 56Mn exposed groups, respectively, changes in large intestinal microflora were evident. After 6 hours and on day 3 after 56Mn exposure amount of main representatives of large intestinal microflora (Bifidobacterium and lactobacilli) was decreased in the dose dependent manner. On the other hand, the amount of conditionally pathogenic bacteria was increased. These changes were persistent even on day 14. External 60Co γ-irradiation at a dose of 2 Gy also changed the intestinal microflora, but these changes were not persistent and on day 14 after irradiation returned to the control level. Our data suggest that internal exposure to dispersed powdered 56Mn has a significant biological impact on the intestinal microflora for a prolonged period of time, when it is compared with the effects of external radiation.

The Third International Intercomparison on EPR Tooth Dosimetry: part 2, final analysis

The objective of the Third International Intercomparison on EPR Tooth Dosimetry was to evaluate laboratories performing tooth enamel dosimetry <300 mGy. Final analysis of results included a correlation analysis between features of laboratory dose reconstruction protocols and dosimetry performance. Applicability of electron paramagnetic resonance (EPR) tooth dosimetry at low dose was shown at two applied dose levels of 79 and 176 mGy. Most (9 of 12) laboratories reported the dose to be within 50 mGy of the delivered dose of 79 mGy, and 10 of 12 laboratories reported the dose to be within 100 mGy of the delivered dose of 176 mGy. At the high-dose tested (704 mGy) agreement within 25% of the delivered dose was found in 10 laboratories. Features of EPR dose reconstruction protocols that affect dosimetry performance were found to be magnetic field modulation amplitude in EPR spectrum recording, EPR signal model in spectrum deconvolution and duration of latency period for tooth enamel samples after preparation.

The 3rd international intercomparison on EPR tooth dosimetry: Part 1, general analysis

The objective of the 3rd International Intercomparison on Electron Paramagnetic Resonance (EPR) Tooth Dosimetry was the evaluation of laboratories performing tooth enamel dosimetry below 300 mGy. Participants had to reconstruct the absorbed dose in tooth enamel from 11 molars, which were cut into two halves. One half of each tooth was irradiated in a 60Co beam to doses in the ranges of 30-100 mGy (5 samples), 100-300 mGy (5 samples), and 300-900 mGy (1 sample). Fourteen international laboratories participated in this intercomparison programme. A first analysis of the results and an overview of the essential features of methods applied in different laboratories are presented. The relative standard deviation of results of all methods was better than 27% for applied doses in the range of 79-704 mGy. In the analysis of the unirradiated tooth halves 8% of the samples were identified as outliers with additional absorbed dose above background dose.

Comparison of sample preparation and signal evaluation methods for EPR analysis of tooth enamel

In dose reconstruction by EPR dosimetry with teeth various methods are applied to prepare tooth enamel samples and to evaluate the dosimetric signal. A comparison of seven frequently used methods in EPR dosimetry with tooth enamel was performed. The participating Institutes have applied their own procedure to prepare tooth enamel samples and to evaluate the dosimetric signal. The precision of the EPR measurement and the dependence of the estimated dosimetric signal with irradiation up to 1000 mGy were compared. The obtained results are consistent among the different methods. The reproducibility of the dosimetric signal and its estimated relation with the absorbed dose was found to be very close for the applied methods with one possible exception.

Estimation of dose absorbed fraction for 131I-beta rays in rat thyroid

The dose absorbed fraction of rat thyroid by internal deposit of 131I has been calculated as a function of effective diameter of thyroid. The calculations were done using two types of Monte Carlo simulations: one was by a simple energy-loss calculation in spherical volume according to the electron stopping power, and another by a more realistic simulation using Monte Carlo N-Particle Transport code system Version 4A (MCNP). These two calculations were consistent with each other within a deviation of 5%. The absorbed fractions in spherical thyroid were drastically changed up to 5 mm diameter, and then almost all energy was deposited within 10 mm diameter. For the practical application to the animal experiment, the absorbed fractions of ellipsoid-shaped thyroids were also calculated for 1-, 4- and 9-week-old rats, where the fractions were estimated to be 0.61, 0.67 and 0.68, respectively. It was also found that the absorbed fraction of the ellipsoid with various dimensions can be simulated by a calculation for spherical volume with a comparable effective diameter.