Issues
Thyroid dose estimations in fetus and new-borns after the Chernobyl accident
"Radiation and Risk" 1997. Vol. 10, pp.118-124
Authors
Zvonova I.A.
St.Petersburg Institute of Radiation Hygiene of the Ministry of Health of Russia
Abstract
A method of a dose estimation in fetal thyroid due to 131I intake into mother’s body living on a territory contaminated with radionuclides after the Chernobyl accident is described. The initial value for calculations was the thyroid dose in mother formed due to a prolonged 131I intake with contaminated food and air. The absorbed fetal thyroid dose is dependent on pregnancy time on the day of radioactive fallout. It did not differ from the average tissue dose during pregnancy less than 75 days and was the highest, approximately twice as high as the mother’s thyroid dose in case when the age of fetus was from 100 to 140 days at the time of accident. The fetal thyroid dose became smaller with increasing of fetal age. The thyroid dose in a new-born child could be formed due to a prenatal 131I uptake in fetal thyroid and due to 131I intake with maternal milk after its birth if the accident happened at the last month of a pregnancy. The thyroid dose in a breast-feed new-born was higher by a factor of 3.5±0.2 than a thyroid dose in its mother following the Chernobyl accident.
Key words
Doses of exposure, fetal thyroid, prenatal 131I uptake, radionuclide, placental transition, Chernobyl accident, radioactive fallout, contaminated areas, absorbed dose, gestational age.
References
1. NCRP, Report 80. Induction of thyroid cancer by ionizing radiation. National Council on Radiation Protection and Measurements, Bethesda, Maryland, 1985.
2. Johnson J.R. Fetal thyroid dose from intakes of radioiodine by the mother. Health Phys. 1982. Vol. 43, No. 4. PP. 573-582.
3. Zvonova I.A. and Balonov M.I. Radioiodine Dosimetry and Forecast for Consequences of Thyroid Exposure of the RSFSR Inhabitants Following the Chernobyl Accident//The Chernobyl Papers. V. I: Doses to the Soviet Population and Early Health Effects Studies. Eds. by S. Merwin and M. Balonov. Research Enterprises, 1993. PP. 71-125.
4. Balonov M.I., Brook G.Ya., Golikov V.Yu., Erkin V.G., Zvonova I.A., Parkhomenko V.I., Shutov V.N. Irradiation of the population of the Russian Federation due to the accident at the Chernobyl NPP. Radiation and Risk. 1996. Vol. 7. PP. 39-71. P>
5. Zvonova I.A., Balonov M.I., Bratilova A.A. et al. Estimation of the absorbed dose in the thyroid gland of the inhabitants of the Bryansk, Tula, and Oryol regions according to the results of radiometry in 1986. Radiation and Risk. This issue. PP. 95-116. P>
6. Rubov S. and Klopper J. Excretion of radioiodine in human milk following a therapeutic dose of 131I. Eur. J. Nucl. Med. 1988. Vol. 14. PP. 632-633.
7. Weaver J.C., Kamm M.L. and Dobson R.L. Excretion of radioiodine in human milk. JAMA. 1960. Vol. 173. PP. 872-875.
8. ICRP Publication 56. Age-dependent Doses to Members of the Public from Intake of Radionuclides. Annals of the ICRP. Vol. 20, 1989.