Autor: |
Drozdovitch V; Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, 9609 Medical Center Drive, Room 7E548 MSC 9778, Bethesda, MD, 20892-9778, USA. drozdovv@mail.nih.gov., Khrouch V; State Research Center, Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Moscow, Russia., Minenko V; Institute for Nuclear Problems, Belarusian State University, Minsk, Belarus., Konstantinov Y; Institute of Radiation Hygiene, Saint Petersburg, Russia., Khrutchinsky A; Institute for Nuclear Problems, Belarusian State University, Minsk, Belarus., Kutsen S; Institute for Nuclear Problems, Belarusian State University, Minsk, Belarus., Kukhta T; United Institute of Informatics Problems, Minsk, Belarus., Shinkarev S; State Research Center, Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Moscow, Russia., Gavrilin Y; State Research Center, Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Moscow, Russia., Luckyanov N; U.S. National Cancer Institute (retired), Bethesda, MD, USA., Voillequé P; MJP, Risk Assessment, Inc, Denver, CO, USA., Bouville A; U.S. National Cancer Institute (retired), Bethesda, MD, USA. |
Abstrakt: |
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 131 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 131 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. The assessment of the contributions of the external and internal contamination of the body to the radiation signal is divided into two parts: (1) the estimation of the radionuclide activities deposited on, and incorporated in, various parts of the body, and (2) the responses of the radiation detectors to the gamma rays emitted by the radionuclides deposited on, and incorporated in, various parts of the body. The first part, which is presented in this paper, includes a variety of exposure scenarios, models, and calculations for 17 of the most abundant gamma-emitting radionuclides contributing to the thyroid detector signal, while the second part is presented in a companion paper. The results presented in the two papers were combined to calculate the contributions of the external and internal contamination of the body to the radiation signal, and, in turn, the 131 I activities in the thyroids of all subjects of an epidemiologic study of thyroid cancer and other thyroid diseases among 11,732 Belarusian-American cohort members who were exposed in childhood and adolescence. |