Risk analysis of the mortality from the diseases of the circulatory system in the Ural cohort of emergency-irradiated population for the years 1950–2015

The paper describes for the first time the results of the radiation effect study using the example of the analysis of circulatory system disease mortality in newly established cohort combining the population exposed in 1950–1960 due to 2 radiation incidents in the Southern Urals (the Techa River and East-Urals radioactive Trace). The cohort consists of 60,205 people. Over a 65-year follow up period 14,830 deaths from all diseases of the circulatory system were registered. Out of this number 6,163 deaths were from ischemic heart disease, and 4,388 deaths were from cerebrovascular diseases. Analysis was performed on the basis of individualized estimates of dose accumulated in muscle tissue (both internal and external components of the dose), calculated with new Techa River Dosimetry System 2016. As per the latest calculations, mean dose to muscle tissue in members of the combined cohort was 34 mGy, maximum dose was 995 mGy. Simple parametric model of excess relative risk (ERR) was used in the analysis. The number of person-years at risk was 1836,203. The findings of the analysis show linear increase of mortality risk per unit dose from all the disease of circulatory system (ERR/100 mGy was 3%; 95% CI: 0,8%; 5,2%) and from ischemic heart disease (ERR/100 mGy was 9,2%; 95% CI: 5,4%; 13,5%). with 15-year latent period. No statistically significant increase in mortality from the cerebrovascular diseases in the combined cohort of the population exposed in the Southern Urals over a 65-year period received evidence. The obtained results are in good agreement with those received in the analysis of the effect in the Techa River Cohort in 2013. The latter covered a 53-year period (with minimum latent period of 15 years) and revealed statistically significant linear dose response for all diseases of the circulatory system (ERR/100 mGy – 0.036) and ischemic heart disease (ERR/100 mGy – 0.056).

1. Preston DL, Shimizu Y, Pierce DA, Suyama A, Mabuchi K. Studies of the mortality of atomic bomb survivors. Report 13: solid cancer and noncancer disease mortality: 1950-1997. Radiation Res. 2003; 160 (4): 381-407.

2. Shimizu Yu, Kodama K, Nishi N, Kasagi F, Suyama A, Soda M, Grant EJ, Sugiyama H, Sakata R, Moriwaki H, Hayashi M, Konda M, Shore RE. Radiation exposure and circulatory disease risk: Hiroshima and Nagasaki atomic bomb survivor data, 1950-2003. BMJ. 2010; 340 doi: https://doi.org/10.1136/bmj.b5349

3. Ivanov VK. Late Cancer and noncacer risks among Chernobyl emergency workers of Russia. Health Phys. 2007; 93: 470-479.

4. Little MP, Tawn EJ, Tzoulaki I, Wakeford R, Hildebrandt G, Paris F, Tapio S, Elliot P. Review and meta-analysis of epidemiological associations between low or moderate doses of ionizing radiation and circulatory disease risks, and their possible mechanisms. Radiat Environ Biophys. 2010; 49 (2):139-153.

5. Azizova TV, Muirhead CR, Druzhinina MB, Grigoryeva ES, Vlasenko EV, Sumina MV, O’Hagan JA, Zhang W, Haylock RGE and Hunter N. Cardiovascular Diseases in the Cohort of Workers First Employed at Mayak PA in 1948–1958. Radiat Res. 2010; 174:155-168.

6. Akleyev A.V. [et al.]. Health status of the population residing in the South Urals territories contaminated with radionuclides. Moscow: RADECON, 2001, 194 p. (in Russian)

7. Krestinina LY, Epifanova S, Silkin S, Mikryukova L, Degteva M, Shagina N, Akleyev A. Chronic low-dose exposure in the Techa River Cohort: risk of mortality from circulatory diseases. Radiat Environ Biophys. 2013; 52: 47–57; DOI: 10.1007/s00411-012-0438-5.

8. Krestinina LY, Akleev AV. Long-term somatic-stochastic effects. Edited. by AV. Akleev. Consequences of radioactive contamination of the Techa River. Chelyabinsk, 2016, Chapter 9, pp. 270-330. (in Russian)

9. Tolstykh EI, Degteva MO, Peremyslova LM, Shagina NB, Vorobiova MI, Anspaugh LR, Napier BA. Reconstruction of long-lived radionuclide intakes for Techa riverside residents: 137Cs. Health Phys. 2013; 104(5):481–498.

10. Tolstykh EI, Peremyslova LM, Degteva MO, Napier BA. Reconstruction of radionuclide intakes for the residents of East Urals Radioactive Trace (1957-2011). Radiat. Environ. Biophys., 2017, 56, pp. 27-45; DOI 10.1007/s00411-016-0677-y.

11. Shagina NB, Tolstykh EI, Degteva MO, Anspaugh LR, Napier BA. Age and gender specific biokinetic model for strontium in humans. J Radiol Prot. 2015; 35(1):87-127.

12. Preston DL, Lubin J, Pierce D, and McConney. Epicure Users Guide. Seattle, Washington: Hirosoft International Company; c 1993.