RADIATION & RISK
Bulletin of the National Radiation and Epidemiological Registry
since 1992
About the Journal : 2014 : vol. 23, No. 3 : Radiation risks of thyroid cancer among the Chernobyl emergency workers

Radiation risks of thyroid cancer among the Chernobyl emergency workers

«Radiation and Risk», 2014, vol. 23, No. 3, pp.14-25

Authors

Gorsky A.I. – Lead. Researcher, C. Sc., Tech., Medical Radiological Research Center, Ministry of Health of the Russian Federation, Obninsk, Russia. Contacts: 4 Korolyov str., Obninsk, Kaluga region, Russia, 249036. Tel.: (484) 399-32-45; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it. .
Maksioutov M.A. – Head of Lab., C. Sc., Tech., Medical Radiological Research Center, Ministry of Health of the Russian Federation, Obninsk, Russia.
Tumanov K.A. – Senior Researcher, C. Sc., Biol., Medical Radiological Research Center, Ministry of Health of the Russian Federation, Obninsk, Russia.
Kashcheev V.V. – Senior Researcher, C. Sc., Biol., Medical Radiological Research Center, Ministry of Health of the Russian Federation, Obninsk, Russia.
Chekin S.Yu. – Senior Researcher;
Ivanov V.K. – Chairman of RSCRP, Deputy Director, Corresponding Member of RAS, Medical Radiological Research Center, Ministry of Health of the Russian Federation, Obninsk, Russia.

Abstract

The paper presents results of analysis of thyroid cancer incidence among males participated in clean-up work within the 30-km Chernobyl exclusion zone from the 26th April through the 31st De-cember 1986. The considered follow up period of the cohort made up of 27749 emergency workers (EWs), residents of six regions of the European part of Russia, is 1992-2010. The analysis was based on data of the National Radiation Epidemiology Registry (NRER). All cohort members have documented radiation dose from external exposure. The cohort consisted of two groups of the accident workers, the group 1 consists of 5650 so called "exposed" EWs worked from April 26 to May 31 and exposed both to external radiation and 131I; the group 2 of so called "unexposed" EWs consists of 22099 males worked within the zone from June through December 1986, and exposed to external radiation only. For the whole period of follow-up 49 thyroid cancer cases were registered. For estimating risk of thyroid cancer associated with exposure to 131I and exact confidential limits the data of "exposed" vs. "unexposed" contingency tables were used. For calculating risk of thyroid cancer associated with external exposure only (the group 2) the maximum likelihood estimation for relative risk linear model was used. The odds ratio is 1.4 (0.71, 2.70 90% CI). Excess relative risk per 1 Gy in the group 2 ("unexposed") is 1.87 (-2.16, 26.38 90% CI). The calculated mean radiation dose to the thyroid from 131I is 0.22 (0.05, 0.70 90% CI) Gy. According to obtained estimates, contribution of 131I to radiation associated thyroid cancer among EWs worked in the 30-km Chernobyl exclusion zone in May 1986 is 53%.

Key words
Thyroid cancer, radiation risk, emergency workers, Chernobyl accident, documented dose, external radiation exposure, 131I, odds ratio, excess relative risk, linear model of risk.

References

1. Preston D.L., Ron E., Tokuoka S., Funamoto S., Nishi N., Soda M., Mabuchi K., Kodama K. Solid cancer incidence in atomic bomb survivors: 1958-1998. Radiat. Res., 2007, vol. 168, no. 1, pp. 1-64. 2. Hancock S.L., Cox R.S., McDougall I.R. Thyroid diseases after treatment of Hodgkin’s disease. N. Engl. J. Med., 1991, vol. 325, no. 9, pp. 599-605.

3. Sont W.N., Zielinski J.M., Ashmore J.P., Jiang H., Krewski D., Fair M.E., Band P.R., Létourneau E.G. First analysis of cancer incidence and occupational radiation exposure based on the National Dose Registry of Canada. Am. J. Epidemiol., 2001, vol. 153, no. 4, pp. 309-318.

4. Ivanov V.K., Gorski A.I., Maksioutov M.A., Vlasov O.K., Godko A.M., Tsyb A.F., Tirmarche M., Valenty M., Verger P. Thyroid cancer incidence among adolescents and adults in the Bryansk region of Russia fol-lowing the Chernobyl accident. Health Phys., 2003, vol. 84, no. 1, pp. 46-60.

5. Ivanov V.K., Tsyb A.F., Petrov A.V., Maksioutov M.A., Shilyaeva T.P., Kochergina E.V. Thyroid cancer incidence among liquidators of the Chernobyl accident: absence of dependence of radiation risks on external radiation dose. Radiat. Environ. Biophys., 2002, vol. 41, no. 3, pp. 195-198.

6. Ivanov V.K., Chekin S.Yu., Kashcheev V.V., Maksioutov M.A., Tumanov K.A. Risk of thyroid cancer among Chernobyl emergency workers of Russia. Radiat. Environ. Biophys., 2008, vol. 47, no. 4, pp. 463-467.

7. Kesminiene A., Evrard A.S., Ivanov V.K., Malakhova I.V., Kurtinaitise J., Stengrevics A., Tekkel M., Chekin S.Yu., Drozdovitch V., Gavrilin Y., Golovanov I., Kryuchkov V.P., Maceika E., Mirkhaidarov A.K., Polyakov S., Tenet V., Tukov A.R., Byrnes G., Cardis E. Risk of thyroid cancer among Chernobyl liquidators. Radiat. Res., 2012, vol. 178, pp. 425-436; DOI: 10.1667/RR2975.1.

8. Breslow N.E., Day N.E. Statistical methods in cancer research. IARC Scientific Publication No 82. Lyon, IARC, 1987.

9. Ivanov V.K., Gorsky A.I., Kashcheev V.V., Maksioutov M.A., Tumanov K.A. Latent period in induction of radiogenic solid tumors in the cohort of emergency workers. Radiat. Environ. Biophys., 2009, vol. 48, no. 3, pp. 247-252.

10. UNSCEAR 2006 report. Effect of ionizing radiation. United Nation scientific committee on the effects of atomic radiation. New York, United Nation, 2008. 105 p.

Full-text article (in Russian)