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.

ICRP Publication 141: Occupational Intakes of Radionuclides: Part 4.

The 2007 Recommendations (ICRP, 2007) introduced changes that affect the calculation of effective dose, and implied a revision of the dose coefficients for internal exposure, published previously in the Publication 30 series (ICRP, 1979a,b, 1980a, 1981, 1988) and Publication 68 (ICRP, 1994b). In addition, new data are now available that support an update of the radionuclide-specific information given in Publications 54 and 78 (ICRP, 1989a, 1997) for the design of monitoring programmes and retrospective assessment of occupational internal doses. Provision of new biokinetic models, dose coefficients, monitoring methods, and bioassay data was performed by Committee 2 and its task groups. A new series, the Occupational Intakes of Radionuclides (OIR) series, will replace the Publication 30 series and Publications 54, 68, and 78. OIR Part 1 (ICRP, 2015) describes the assessment of internal occupational exposure to radionuclides, biokinetic and dosimetric models, methods of individual and workplace monitoring, and general aspects of retrospective dose assessment. OIR Part 2 (ICRP, 2016), OIR Part 3 (ICRP, 2017), this current publication, and the final publication in the OIR series (OIR Part 5) provide data on individual elements and their radioisotopes, including information on chemical forms encountered in the workplace; a list of principal radioisotopes and their physical half-lives and decay modes; the parameter values of the reference biokinetic models; and data on monitoring techniques for the radioisotopes most commonly encountered in workplaces. Reviews of data on inhalation, ingestion, and systemic biokinetics are also provided for most of the elements. Dosimetric data provided in the printed publications of the OIR series include tables of committed effective dose per intake (Sv per Bq intake) for inhalation and ingestion, tables of committed effective dose per content (Sv per Bq measurement) for inhalation, and graphs of retention and excretion data per Bq intake for inhalation. These data are provided for all absorption types and for the most common isotope(s) of each element. The online electronic files that accompany the OIR series of publications contains a comprehensive set of committed effective and equivalent dose coefficients, committed effective dose per content functions, and reference bioassay functions. Data are provided for inhalation, ingestion, and direct input to blood. This fourth publication in the OIR series provides the above data for the following elements: lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), actinium (Ac), protactinium (Pa), neptunium (Np), plutonium (Pu), americium (Am), curium (Cm), berkelium (Bk), californium (Cf), einsteinium (Es), and fermium (Fm).

INDIVIDUAL RADIOLOGICAL MONITORING AFTER MAJOR RELEASES OF RADIONUCLIDES TO THE ENVIRONMENT. / INDYVIDUAL'NYI RADIOLOGIChNYI MONITORYNG PISLIa ZNAChNYKh VYKYDIV RADIONUKLIDIV U NAVKOLYShNIe SEREDOVYShchE.

Nuclear installations may contain a large inventory of radioactive material and an emergency caused by an accident, natural disaster, or malevolent act may cause uncontrolled releases of radionuclides to the environment. The paper presents a brief overview of individual radiological monitoring in case of major releases of radionuclides to the environment and introduces the new Report 92 of the International Commission on Radiation Units and Measurements (ICRU) on Radiation Monitoring for Protection of the Public after Major Releases of Radionuclides to the Environment. The Report was prepared taking into account the results of the research «Development of the program for radiation and hygienic monitoring for the radiological protection of human under radiation accidents and acts of nuclear terrorism¼ which was carried out in the internal dosimetry laboratory of the NRCRM of NAMS of Ukraine in 2016-2018. The Report Committee was headed by the scientific supervisor of the research, the Committee consisted of leading experts from UK, Italy, China, Germany, Russia, Slovenia, United States, Ukraine, Japan, and experts from the International Atomic Energy Agency. The preparation of the Report was supported by the US Environmental Protection Agency, US Nuclear Regulatory Commission, US Department of Energy, National Academy of Medical Sciences of Ukraine, and Radiation Protection Institute of the ATS of Ukraine.

IMIE computer codes: 10 y in the internal dosimetry.

The 'Individual Monitoring for Internal Exposure' (IMIE) computer codes are the family of interactive tools for interpretation of the bioassay data and individual dose assessments. During 10 y of the IMIE evolution, the extensive experience in the IMIE application has been accumulated and the underlying methodology has undergone essential improvements. The main distinguished feature of the IMIE ideology is the automated numerical analysis of all examined exposure scenarios with the succeeding interactive identification of events of intake(s) and assessment of associated doses. The numerical deconvolution algorithms and the massive library of tabulated 'bioassay/dose response functions' are employed for the processing of an arbitrary pattern of intake and complex exposure conditions. This article discusses details implemented in the IMIE algorithms and examples of IMIE application.

Design and operation of the internal dosimetry program for the Chornobyl 'shelter implementation plan'.

The paper discusses the system of individual monitoring for internal exposure, deployed by the Ukrainian Radiation Protection Institute as an integral component of the Shelter Implementation Plan (SIP) at the Chornobyl industrial site. SIP anticipates involving of up to 10,00 workers of numerous SIP contractors. A typical daily shift comprises several hundred workers. Most of them have a direct contact with the irradiated nuclear fuel, fuel-contained aerosols and other contaminated materials on the industrial site. The hierarchical SIP individual monitoring program has been designed with consideration of peculiarities of SIP exposure conditions and aims at the timely and reliable identification of intakes, assessment of doses and initiation of measures for prevention of further intakes.

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.

Internal doses to Ukrainian populations using Dnieper River water.

The dynamics of internal doses from 137CS and 90Sr as a consequence of the use of Dnieper River water were calculated. Local peculiarities of municipal tap, irrigation, and fish consumption in the Ukraine were considered. The dynamics of 90Sr accumulation in human bone as a result of the use of Dnieper water is simulated. The dose predictions are based on de facto data and the stochastic forecast of radionuclide concentrations in Dnieper reservoirs. A large array of statistical data on the age-structures of exposed populations, food consumption rate, agricultural production, fish contamination, and site-specific parameters were used. Exposures are estimated for 12 regions of the Dnieper basin and the Crimea Republic. The maximal individual annual committed effective doses are 1.7 X 10(-5) and 2.7 X 10(-5) Sv from 90Sr and 137Cs, respectively, due to the use of water in 1986 by members of the population in the Kievska region. Commercial fishermen on the Kievska reservoir, who consumed 360 kg y(-1) of fish in 1986, received 4.7 X 10(-4) and 5 X 10(-3) Sv from 90Sr and 137Cs, respectively. The contributions to the collective (over 70 y) effective dose of irrigation, municipal tap water, and fish consumption for members of the general public, respectively, are 18%, 43%, 39% in the Kievska region; 8%, 25%, 67% in the Poltavska region; 50% 50%, 0% (no Dnieper fish consumed) in the Crimea Republic. The predicted contribution of 90Sr to collective dose resulting from the use of water is 80%. The collective dose to the population of the Dnieper regions (32.5 million people) is 3,000 person-Sv, due to the use of water.

'Dose per unit content' functions: a robust tool for the interpretation of bioassay data.

The purposes of this study were to investigate the influence of the consequences of the lack of primary bioassay information and to elaborate approaches which could improve the reliability of dose assessments. The aggregated time-dependent functions 'dose per unit organ (excretion) content' z(t) have been proposed in this study as a convenient and reliable tool for bioassay. The analysis of the variation of z with changes of AMAD has demonstrated the existence of areas of the relative invariance of z, which permits the selection of one (reference) function z for the whole area of stability. Within the framework of such an approach an arbitrary set of bioassay data can be approximated by the linear combination F(t) = sum(i) E(i)/z(t - tau(i)), where F(t) = function of time t, which approximates the observed bioassay time trend; tau(i) = time shift of the acute intake i; E(i) = effective dose, associated with the acute intake i (the two last parameters are results of the approximation procedure).

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.

Estimation of the thyroid doses for ukrainian children exposed in utero after the chernobyl accident.

This paper describes methods for estimating thyroid doses to Ukrainian children who were subjects of an epidemiological study of prenatal exposure and presents the calculated doses. Participants were 2,582 mother-child pairs in which the mother had been pregnant at the time of the Chernobyl accident on 26 April 1986 or in the 2-3 mo following when (131)I in fallout was still present. Among these, 1,494 were categorized as "exposed;" a comparison group of 1,088 was considered "relatively unexposed." Individual in utero thyroid dose estimates were found to range from less than 1 mGy to 3,200 mGy, with an arithmetic mean of 72 mGy. Thyroid doses varied primarily according to stage of pregnancy at the time of exposure and level of radioactive contamination at the location of residence. There was a marked difference between the dose distributions of the exposed and comparison groups, although nine children in the latter group had calculated doses in the range 100-200 mGy. For those children who were born after the accident and prior to the end of June 1986, postnatal thyroid doses were also estimated. About 7.7% (200) of the subjects received thyroid doses after birth that were at least 10% of their cumulative doses.