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. 2014 Mar;106(3):370-96.
doi: 10.1097/HP.0b013e31829f3096.

Thyroid cancer study among Ukrainian children exposed to radiation after the Chornobyl accident: improved estimates of the thyroid doses to the cohort members

Affiliations

Thyroid cancer study among Ukrainian children exposed to radiation after the Chornobyl accident: improved estimates of the thyroid doses to the cohort members

Ilya Likhtarov et al. Health Phys. 2014 Mar.

Abstract

In collaboration with the Ukrainian Research Center for Radiation Medicine, the U.S. National Cancer Institute initiated a cohort study of children and adolescents exposed to Chornobyl fallout in Ukraine to better understand the long-term health effects of exposure to radioactive iodines. All 13,204 cohort members were subjected to at least one direct thyroid measurement between 30 April and 30 June 1986 and resided at the time of the accident in the northern parts of Kyiv, Zhytomyr, or Chernihiv Oblasts, which were the most contaminated territories of Ukraine as a result of radioactive fallout from the Chornobyl accident. Thyroid doses for the cohort members, which had been estimated following the first round of interviews, were re-evaluated following the second round of interviews. The revised thyroid doses range from 0.35 mGy to 42 Gy, with 95% of the doses between 1 mGy and 4.2 Gy, an arithmetic mean of 0.65 Gy, and a geometric mean of 0.19 Gy. These means are 70% of the previous estimates, mainly because of the use of country-specific thyroid masses. Many of the individual thyroid dose estimates show substantial differences because of the use of an improved questionnaire for the second round of interviews. Limitations of the current set of thyroid dose estimates are discussed. For the epidemiologic study, the most notable improvement is a revised assessment of the uncertainties, as shared and unshared uncertainties in the parameter values were considered in the calculation of the 1,000 stochastic estimates of thyroid dose for each cohort member. This procedure makes it possible to perform a more realistic risk analysis.

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Figures

Fig. 1
Fig. 1
General scheme of the TD-10 thyroid dose reconstruction system.
Fig. 2
Fig. 2
Representation of the Monte-Carlo simulation system developed in TD-10 for the estimation of the ecological and instrumental thyroid doses and of their uncertainties.
Fig. 3
Fig. 3
Cumulative 131I ground deposition density (MBq m−2) in the northern part of Ukraine where the cohort members resided at the time of the accident (map in the upper left part of the Figure) and distribution of the cohort members over the eight most contaminated raions of Kyiv, Zhytomyr and Chernihiv Oblasts. At the time of the accident, 150 members of the cohort resided outside those eight raions.
Fig. 4
Fig. 4
Examples of daily fallout of 131I and of the time dynamics of the total deposition on the ground estimated by means of the atmospheric transport model LEDI for several locations (Talerko et al. 2005b): Chernihiv-city (a), Poliske, Kyiv Oblast (b), Novi Petrivci, Kyiv Oblast (c), Narodychi, Zhytomyr Oblast (d).
Fig. 5
Fig. 5
Procedure of empirical estimation of the radiocesium contribution (calibration factor) to the signal registered near the neck using an anthropomorphic phantom contaminated with 137Cs (the example shown is for the spectrometer NK-350)
Fig. 6
Fig. 6
Variation with time after the accident of the relative contribution of the radiocesiums to the detector’s signal (left vertical axis) and of the number of measured cohort members (right vertical axis).
Fig. 7
Fig. 7
Age- dependent thyroid mass for boys and girls of Kyiv and Chernihiv Oblasts (filled circles) and Zhytomyr Oblast (open circles).
Fig. 8
Fig. 8
Scheme of assignment of the daily consumption rate of milk according to the questionnaires used in TD-10.
Fig. 9
Fig. 9
Illustrations of distributions of individual ecological and instrumental doses and of related quantities obtained from the Monte-Carlo simulations: a) example of a subject with “simple” behavior (without relocation), b) example of a subject with multiple relocations during May-June of 1986.

References

    1. Balonov M, Kaidanovsky G, Zvonova I, Kovtun A, Bouville A, Luckyanov N, Voillequé P. Contributions of short-lived radioiodines to thyroid doses received by evacuees from the Chornobyl area estimated using early in-vivo measurements. Radiat Prot Dosim. 2003;105:593–599. - PubMed
    1. Barkhudarov RM, Gordeev KI, Dibobes IK, Likhtarev IA, Margulis UY, Osanov DP, Pavlovsky OA, Prister BS, Savkin MN, Shamov VP. Methodological principles for calculating levels of external and internal exposure of the population used in taking strategic decisions. In: Romanenko AE, editor. Medical aspects of the Chernobyl accident. Vienna: International Atomic Energy Agency; 1989. pp. 171–182. IAEA-TECDOC-516.
    1. Carrroll RJ, Ruppert D, Stefanski LA, Crainiceanu CM. Measurement Error in Nonlinear Models: A Modern Perspective. 2. Chapman & Hall/CRC; Boca Raton: 2006.
    1. Chepurny M. Accounting for the effect of incorporated cesium isotopes on the activity measured in thyroid. Proceedings of International Scientific and Practical conference: Epidemiology of medical consequences of the Chernobyl accident; Kyiv. October 9–10, 2007; Kyiv: 2007. pp. 23–24. (in Russian)
    1. Coughtrey PJ. Commission of the European Communities report EUR 12608 EN. Luxembourg: Radioactivity Transfer to Animal Products. 1990

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