Radiation Dose Does Not Affect the Predictive Value of Thyroid Biopsy for Diagnosing Papillary Thyroid Cancer in a Belarusian Cohort Exposed to Chernobyl Fallout.

Introduction: The Chernobyl nuclear accident exposed residents of contaminated territories to substantial quantities of radioiodines and was followed by an increase in thyroid cancer, primarily papillary thyroid cancer (PTC), among exposed children and adolescents. Although thyroid biopsy is an essential component of screening programs following accidental exposure to radioiodines, it is unknown whether the predictive value of biopsy is affected by different levels of environmental exposure.

Methods: A cohort of 11,732 Belarusians aged ≤18 years at the time of the Chernobyl accident with individual thyroid radiation dose estimates was screened at least once 11-22 years later.

Recall of residential history and dietary habits during pregnancy and lactation in the distant past: reliability of questionnaire-based radiation doses for persons exposed in utero and early life.

This study evaluates the reliability of information obtained by standardized questionnaires used in by personal interviews for estimation of radiation thyroid doses of 1065 individuals in the Belarusian cohort of individuals who were exposed in utero and early life following the Chernobyl accident in April 1986. Data from two interviews conducted in 2012-2017 and in 2018-2022 with mothers, who were pregnant or gave birth shortly after the Chernobyl accident, were analysed. The most reliable answers dealt with various attributes related to residential history.

Doses from external irradiation and ingestion of Cs, Cs and Sr of the population of Belarus accumulated over 35 years after the Chernobyl accident.

This study considers the exposure of the population of the most contaminated Gomel and Mogilev Oblasts in Belarus to prolonged sources of irradiation resulting from the Chernobyl accident. Dose reconstruction methods were developed and applied in this study to estimate the red bone-marrow doses (RBMs) from (i) external irradiation from gamma-emitting radionuclides deposited on the ground and (ii) Cs, Cs and Sr ingestion with locally produced foodstuffs. The mean population-weighted RBM doses accumulated during 35 years after the Chernobyl accident were 12 and 5.

Evaluation of I transfer in the environment based on the available measurements made in Belarus after the Chernobyl accident.

This study evaluates the I transfer from ground deposition to the human thyroid gland after the Chernobyl accident using measurements of I concentrations in 1,252 soil, 124 grass, and 136 cow's milk samples as well as I thyroid activity measured in 3,100 individuals included in the Belarusian-American cohort. The following parameters of an I environmental transfer model used to calculate thyroid doses were evaluated in this study: (i) the interception factor of I by pasture grass, which was described by a purely empirical equation, (ii) the removal rate of I from pasture grass due to weathering and growth dilution, estimated to be 0.0676 d (half-life of 10.

Thyroid dose estimates for the genome-wide association study of thyroid cancer in persons exposed in Belarus to 131I after the Chernobyl accident.

The Chernobyl accident on 26 April 1986 led to a sharp increase in thyroid cancer (TC) incidence in the individuals exposed to radiation in childhood. The major risk factor for TC was exposure to Iodine-131 (131I). Here, we estimated the thyroid doses due to 131I intake for 2041 participants of the genome-wide association study of TC in Belarusian people exposed to radioactive fallout from the Chernobyl accident.

Estimation of radiation gonadal doses for the American-Ukrainian trio study of parental irradiation in Chornobyl cleanup workers and evacuees and germline mutations in their offspring.

Radiation doses of parents exposed from the Chornobyl accident as cleanup workers or evacuees were estimated in the National Cancer Institute-National Research Center for Radiation Medicine trio (i.e. father, mother, offspring) study aimed at investigating the radiation effects on germlinemutations in children as well as other outcomes.

Reliability of thyroid doses due to I intake exceeding 5 Gy in a cohort of Belarusian children exposed to Chernobyl fallout.

High thyroid doses due to Iodine-131 (I) intake among individuals exposed in childhood and adolescence to Chernobyl fallout raise questions about their reliability and their impact on the analysis of the radiation-related risk of thyroid cancer and other thyroid diseases in the exposed population. In the present study, an in-depth examination was conducted of thyroid doses from I intake over 5 Gy calculated for 131 subjects of the Belarusian-American cohort of individuals exposed after the Chernobyl accident. Thyroid doses in this cohort study were estimated based on individual radiation measurements of I thyroidal activity and detailed questionnaire data on individual behavior and consumptions of locally produced foodstuffs.

Activity concentrations of I and other radionuclides in cow's milk in Belarus during the first month following the Chernobyl accident.

The accident at the Chernobyl nuclear power plant (NPP) in Ukraine on April 26, 1986 led to a considerable release of radioactive material resulting in environmental contamination over vast areas of Belarus, Ukraine and western Russian Federation. The major health effect of the Chernobyl accident was an increase in thyroid cancer incidence in people exposed as children and adolescents, so much attention was paid to the thyroid doses resulting from intakes of I. Because cow's milk consumption was the main source of I intake by people, it was important to measure the I activity concentrations in cow's milk to calculate, or to validate, the thyroid doses to the exposed population.

Thyroid Dose Estimates for a Cohort of Belarusian Persons Exposed in Utero and During Early Life to Chernobyl Fallout.

Thyroid radiation doses were estimated for a cohort of 2,965 Belarusian persons who were exposed in utero and during early life to fallout from the Chernobyl nuclear power plant accident. Prenatal and postnatal doses to the thyroid due to intake of I, external irradiation from radionuclides deposited on the ground, and ingestion of cesium isotopes (Cs and Cs) were calculated for all cohort members. Dose estimation was based on personal interviews with subjects' mothers; the interviews collected data on subjects' residential history, consumption by mothers during time of pregnancy and breast-feeding, as well as consumption by subjects after birth.

Belarusian in utero cohort: A new opportunity to evaluate the health effects of prenatal and early-life exposure to ionising radiation.

In April 1986, the Chernobyl nuclear accident resulted in wide-scale contamination of Belarus with significantly elevated levels of radioiodine isotopes, mainly iodine-131 (I), and long-lived radiocaesium isotopes, mainly caesium-137 (Cs). Various groups of the population were affected by exposure to ionising radiation, including pregnant women and their foetuses. This paper describes the methods and results related to the establishment of a cohort of 2965 Belarusian people exposed in utero due to Chernobyl fallout.

Influence of the external and internal radioactive contamination of the body and the clothes on the results of the thyroidal I measurements conducted in Belarus after the Chernobyl accident. Part 1: Estimation of the external and internal radioactive contamination.

The estimation of the thyroid doses received in Belarus after the Chernobyl accident is based on the analysis of exposure-rate measurements performed with radiation detectors placed against the necks of about 130,000 residents. The purpose of these measurements was to estimate the I activity contents of the thyroids of the subjects. However, because the radiation detectors were not equipped with collimators and because the subjects usually wore contaminated clothes, among other factors, the radiation signal included, in addition to the gamma rays emitted during the decay of the I activity present in the thyroid, contributions from external contamination of the skin and clothes and internal contamination of organs other than the thyroid by various radionuclides.

Reliability of Questionnaire Data in the Distant Past: Relevance for Radiation Exposure Assessment.

Interviews with questionnaires are often employed to provide information that may be used for exposure assessment, although the reliability of such information is largely unknown. In this work, the consistency of individual behavior and dietary data collected by means of personal interviews during two study screenings was evaluated. Data were collected for a cohort of about 11,000 persons exposed to 131I in childhood and adolescence shortly after the Chernobyl accident.

Thyroid Dose Estimates for a Cohort of Belarusian Children Exposed to (131)I from the Chernobyl Accident: Assessment of Uncertainties.

Deterministic thyroid radiation doses due to iodine-131 ((131)I) intake were reconstructed in a previous article for 11,732 participants of the Belarusian-American cohort study of thyroid cancer and other thyroid diseases in individuals exposed during childhood or adolescence to fallout from the Chernobyl accident. The current article describes an assessment of uncertainties in reconstructed thyroid doses that accounts for the shared and unshared errors. Using a Monte Carlo simulation procedure, 1,000 sets of cohort thyroid doses due to (131)I intake were calculated.

Thyroid dose estimates for a cohort of Belarusian children exposed to radiation from the Chernobyl accident.

The U.S. National Cancer Institute, in collaboration with the Belarusian Ministry of Health, is conducting a study of thyroid cancer and other thyroid diseases in a cohort of about 12,000 persons who were exposed to fallout from the Chernobyl accident in April 1986.

Database of meteorological and radiation measurements made in Belarus during the first three months following the Chernobyl accident.

Results of all available meteorological and radiation measurements that were performed in Belarus during the first three months after the Chernobyl accident were collected from various sources and incorporated into a single database. Meteorological information such as precipitation, wind speed and direction, and temperature in localities were obtained from meteorological station facilities. Radiation measurements include gamma-exposure rate in air, daily fallout, concentration of different radionuclides in soil, grass, cow's milk and water as well as total beta-activity in cow's milk.