Changes induced in the human respiratory tract by chronic cigarette smoking can reduce the dose to the lungs from exposure to radon progeny.

Chronic cigarette smoking leads to changes in the respiratory tract that might affect the dose received from exposure to radon progeny. In this study, changes induced by cigarette smoking in the respiratory tract were collected from the literature and used for calculation of the dose received by the lungs and organs outside the respiratory tract. Morphological and physiological parameters affected by chronic smoking were implemented in the human respiratory tract model (HRTM) used by the International Commission of Radiological Protection (ICRP). Smokers were found to receive lung doses 3% smaller than the ICRP reference worker (non-smoking reference adult male) in mines and 14% smaller in indoor workplaces and tourist caves. A similar dose reduction was found for the extrathoracic region of the HRTM. Conversely, kidneys, brain, and bone marrow of smokers were found to receive from 2.3- up to 3-fold of the dose received by the respective organ in the ICRP reference worker, although they remained at least two orders of magnitude smaller than the lung dose. These results indicate that the differences in the lung dose from radon progeny exposure in cigarette smokers and non-smokers are smaller than 15%.

RESULTS OF WBC-MONITORING OF FIREFIGHTERS PARTICIPATING IN RESPONSE TO CHORNOBYL FOREST FIRES IN APRIL-MAY 2020. / REZUL'TATY LVL-MONITORYNGU POZhEZhNYKh, ShchO BULY ZADIIaNI U GASINNI LISOVOÏ POZhEZhI V ZONI VIDChUZhENNIa ChAES U KVITNI­TRAVNI 2020 ROKU.

OBJECTIVE: of this study was to determine the levels of radionuclides in the rescuers' bodies of the SES during firefighting in the exclusion zone of the Chornobyl nuclear power plant and to assess the dose of internal radiation dueto this receipt. MATERIALS AND METHODS: From 06.04.2020 to 19.05.2020 in the State Institution «National Research Center forRadiation Medicine of the National Academy of Medical Sciences of Ukraine¼ (NRCRM) measurements of the contentof incorporated gamma radionuclides on whole body counters (WBC) operational class «Screener-3M¼ (Minimumdetected activity (MDA) is 300-500 Bq for 5 minutes of measurement at 137Cs) and expert high-sensitivity WBC (MDAis 20 Bq for 10 minutes of measurement at 137Cs). 470 people (523 measurements) in three groups of personnel ofthe SES of Ukraine who took part in the forest fire liquidation in the exclusion zone in the period from April 4 toMay 5, 2020 were examined. Mathematical and spectrometric methods are used in the work. RESULTS AND CONCLUSIONS: In the vast majority (95 %) of the personnel of the SES of Ukraine, examined at the WBCoperational class «Screener-3M¼ (more than 500 measurements), the assessment of the values of the individualeffective dose of internal radiation due to 137Cs in the body during firefighting, assuming that it receipt occurredduring operation in the exclusion zone, did not exceed the minimum dose detected by MDD (5-14 µSv). The average value of the effective dose of internal radiation in the group of personnel of the State Emergency Service ofUkraine in Kyiv, which participated in the elimination of forest fires in the exclusion zone from April 4 to May 5, 2020(26 people) studied at the expert WBC, is 2.5 ± 1.1 µSv, in the group of personnel of the SES of Ukraine in Cherkasyregion, which participated in the fire on April 19-24, 2020 (9 people) - 2.2 ± 0.6 µSv, in the group of personnel ofthe SES of Ukraine in the Kyiv region, which took part in the elimination of the forest fire in the exclusion zone onApril 4 - May 5, 2020 (42 people) - 4.4 ± 2.4 µSv. Maximum values of 5.1 µSv, 3.5 µSv, 11.8 µSv in the groups ofKyiv city, Cherkasy and Kyiv regions, respectively, which is much lower than the basic dose limit for the populationfrom man-made sources of 1000 µSv · year-1 according to the Law of Ukraine about protection of the person againstinfluence of ionizing radiation.

STATE INSTITUTION «NATIONAL RESEARCH CENTER FOR RADIATION MEDICINE OF THE NATIONAL ACADEMY OF MEDICAL SCIENCES OF UKRAINE¼ - RESEARCH ACTIVITIES AND SCIENTIFIC ADVANCE IN 2017. / REFORMUVANNIa SYSTEMY OKhORONY ZDOROV'Ia: ROL' I MISTsE ZAKLADIV OKhORONY ZDOROV'Ia TRETYNNOGO RIVNIa PRY RADIATsIINYKh NADZVYChAINYKh SYTUATsIIaKh V UMOVAKh VOIeNNOGO STANU.

The role and place of health care facilities of the highly specialized (tertiary) level in radiation emergencies in the conditions of martial law are considered taking into account the experience of overcoming of the Chornobyl catas-trophe consequences. The classification of emergencies and the main scenarios of radiation emergencies (nuclear terrorism, radiation accidents and incidents, the use of nuclear weapons) are presented. The principles of medical preparedness and providing the highly specialized medical care in a radiological emergency are presented on the base of the Chornobyl catastrophe experience. It is determined that the tertiary health care facilities in a radiological emergency should provide as follow: development and implementation of plans and protocols of highly specialized medical care; organization, direct provision, coordination and quality control of the highly specialized medical care; aggregation and coordination of efforts of all three levels of health care facilities; integration into the radiation emergency management system, and analysis and generalization of the experience gained.

Harmonisation of standards for permissible radionuclide activity concentrations in foodstuffs in the long term after the Chernobyl accident.

The article critically examines the practice of post-Chernobyl standardisation of radionuclide concentrations (mainly 137Cs and 90Sr) in food products (FPs) in the USSR and the successor countries of Belarus, Russia and Ukraine. Recommendations are given on potential harmonisation of these standards of radionuclide concentrations in FPs among the three countries, taking into account substantial international experience. We propose to reduce the number of product groups for standardisation purposes from the current amount of several dozens to three to five groups to optimise radiation control and increase the transparency of the process. We recommend five product groups for the standardisation of 137Cs and three groups for 90Sr in food in radiocontaminated areas. The values of standards for individual product groups are recommended to be set proportionally to the measured specific activity in each of these groups, which will reduce unreasonable food rejection. The standards might be set for the entire country, and could be also used to control imports from other countries as well as exports to other countries. The developed recommendations were transferred in 2015-2016 to the regulatory authorities of the three countries.

Main internal dose forming factors for inhabitants of contaminated regions at current phase of the Chernobyl nuclear power plant accident (Kyiv region as an example). / OSNOVNI ChYNNYKY FORMUVANNIa VNUTRIShN'OGO OPROMINENNIa NASELENNIa RADIOAKTYVNO ZABRUDNENYKh TERYTORIY NA POTOChNOMU ETAPI AVARII NA ChAES (NA PRYKLADI KYIVS'KOI OBLASTI).

UNLABELLED: Objective of this work is revealing of main dose forming factors of internal doses for inhabitants of contaminated regions of Kyiv region relying on the results of integral dosimetric monitoring. MATERIALS AND METHODS: Three villages have been chosen for the investigation. They are: Raghivka, Zelena Poliana (Poliske district), Karpylivka (Ivankiv district). Twice a year, in May and in October those villages' residents were inspected for content of incorporated 137Cs. They were measured by direct method at the place of residence with the help of whole body counters (WBC). The principal food samples were collected for detection of 90Sr and 137Сs content. Those villages' inhabitants were interviewed about food consumption levels. Mathematical, dosimetric and radio chemical methods were used in this workResults and conclusions. The estimation of internal doses due to intake of 137Cs by ingestion of milk and potatoes are in the range 0.3-34% of doses estimated on the base of WBC data. The contribution to the dose of internal expo sure from intake of 137Cs with the milk consumption is no more than two times higher than the contribution of pota toes consumption in the case of equal consumption levels of these products. Contributions to the dose of internal exposure from intake of 90Sr with milk and potatoes consumptions are approximately similar. Consumption of mush rooms and other wild nature products by inhabitants from the inspected settlements is the main forming factor of internal dose due to 137Cs intake.

Regulation of the radionuclide content in commodities produced in areas affected by the Chornobyl accident. / Reguljuvannja vmistu radionuklidiv u tovarah, vyroblenyh na terytorijah, shho postrazhdaly vnaslidok avarii' na ChAES.

This paper discusses the approaches to regulation of the content of radionuclides in commodities and compares the international and Ukrainian standards, which establish permissible levels of the content of radionuclides in food-stuffs produced in the Chornobyl-affected areas. The paper gives the actual monitoring data and discusses the main causes of differences between Ukrainian, European and international standards. The need for improvement of current approaches to the regulation of the content of radionuclides in commodities is highlighted.

The sensitivity of different environments to radioactive contamination.

This paper describes modelling calculations carried out to determine the sensitivity of various rural and semi-natural environments to radionuclide contamination by (137)Cs, (90)Sr, and (131)I released during a major nuclear accident. Depositions of 1000 Bq/m(3) were assumed for each radionuclide. Four broad types of environments were considered: agricultural, forest or tundra, freshwater aquatic, and coastal marine. A number of different models were applied to each environment. The annual dose to a human population receiving most or all of its food and drinking water from a given environment was taken as a broad measure of sensitivity. The results demonstrated that environmental sensitivity was highly radionuclide specific, with (137)Cs generally giving the highest doses during the first year, especially for adults, in terrestrial and freshwater pathways. However, in coastal marine environments, (131)I and (239)Pu were more significant. Sensitivity was time dependent with doses for the first year dominating those for the 2nd and 10th years after deposition. In agricultural environments the ingestion dose from (137)Cs was higher for adults than other age groups, whereas for (90)Sr and (131)I, the ingestion dose was highest for infants. The dependence of sensitivity on social and economic factors such as individual living habits, food consumption preferences, and agricultural practices is discussed.