Approaches to the assessment of completeness and quality of the registry of exposed population offspring

Uncertainties of radiation risk of late radiation exposure effects in humans are to a great extent determined by completeness and quality of epidemiological data. The registry of the studied cohort is of fundamental importance for the cohort studies. Particular difficulties appear in the course of development of the exposed population offspring registry as these people in contrast to their parents were not affected by radiation exposure. The formation of the cohort of the exposed population offspring has its peculiarities and requires evaluation of its completeness and quality. The objective of this research is to study the value of the sex ratio as a possible criterion to assess the completeness and quality of the registry of the Techa River Cohort offspring. The register of descendants of the irradiated population at the end of 2019 included information on 25930 persons. The formation of the register of descendants of the population irradiated on the Techa River was started in the mid-1950s. At the same time, various documents were used to confirm the fact of birth of a child in irradiated persons. In the Techa River population the proportion of offspring with exposed mother and unexposed father is 22.2%, those with exposed father and unexposed mother made up 13.9%; the proportion of in utero exposed offspring is 44.6%. In accordance to the widely accepted published data it was to be expected that the number of male 1st-generation offspring in the cohort would be lower. However, the results of the conducted research show no changes in the sex ratio among offspring relative to the population-based control. Moreover, it was stated that the sex ratio in the population of the 1st-generation offspring of the exposed residents of the Techa River settlements should not be viewed as secondary. The assumption about the influence of the pre-conceptional exposure of the parents as well as that of the in utero exposure on changes in the sex ratio was not confirmed. It is shown that the decrease in the value of the sex ratio is associated with misreporting of the male 1st -generation offspring who died in childhood and at young age. The value of the sex ratio in groups formed based on the character and dose of exposure, depended mainly on the source of information used in the course of the offspring registry development.

1. Sources, Effects and Risks of Ionizing Radiation. United Nations Scientific Committee on the Effects of Atomic Radiation. Report to the General Assembly, with Scientific Annexes. United Nations, New York; 2018: 194 p.

2. Vogel F, Motulsky AG. Human genetics. Translated from English. Moscow: Mir; 1989. No. 1. 308 p. (In Russian)

3. Schull WJ, Neel JV, Hashizume A. Some further observations on the sex ratio among infants born to survivors of the atomic bombings of Hiroshima and Nagasaki. American Journal of Human Genetics. 1966;18(4): 328-338.

4. Cox DW. An investigation of possible genetic damage in the offspring of women receiving multiple diagnostic pelvic X-rays. American Journal of Human Genetics. 1964;16: 214-230.

5. Pastukhova EI, Shalaginov SA, Akleyev AV. Secondary sex ratio in population of radioactively contaminated raions of the Chelyabinsk Oblast. Voprosy radiatsionnoy bezopasnosti = Issues of Radiation Safety. 2011;4: 28-37 (In Russian)

6. Allan BB, Brant R, Seidel JE, Jarrell JF. Declining sex ratios in Canada. Canadian Medical Association Journal. 1997;156(1): 37-41.

7. Biggar RJ, Wohlfahrt J, Westergaard T, Melbye M. Sex Ratios, Family Size, and Birth Order. American Journal of Epidemiology. 1999;150: 957-962.

8. Akeyev AV, Novosyolov VN, Shalaginov SA, Burtovaya EYu. Ed. by AV Akleyev. Techa: prior to and after the atomic project. Chelyabinsk; 2015. 345 p. (In Russian)

9. Akeyev AV, Akeyev AA, Blinova EA, Kotikova AI, Tryapitsyna GA, Pryakhin EA, et al. The potential of adaptation to low doses of radiation. Saint-Petersburg: Spetslit; 2019. 111 p. (In Russian)

10. Maconochie N, Roman E, Doyle P, Davies G, Beral V. Sex ratio of nuclear industry employees’ children. Lancet. 2001;357: 1589-1591.

11. Reulen RC, Zeegers MPA, Lancashire E, Winter DL, Hawkins MM. Offspring sex ratio and gonadal irradiation in the British Childhood Cancer Survivor Study. British Journal of Cancer. 2007;96: 1439-1441.

12. Dickinson HO, Parker L, Binks K, Wakeford R, Smith J. The sex ratio of children in relation to paternal preconceptional radiation dose: a study in Cumbria, northern England. Journal Epidemiological Community Health. 1996;50: 645-652.

13. Scherb H, Voigt K. The human sex odds at birth after the atmospheric atomic bomb tests, after Chernobyl, and in the vicinity of nuclear facilities. Environmental Science and Pollution Research International. 2011;5: 697-707.

14. Silkin SS, Krestinina LYu, Startsev NV, Akleyev AV. South Urals Population Exposed to Radiation cohort. Meditsina ekstrem-alnykh situatsiy = Medicine of Extreme Situations. 2019;3: 6170 (In Russian)

15. Degteva MO, Napier BA, Tolstykh EI, Shishkina EA, Shagina NB, Volchkova AYu, et al. Enhancements in the Techa River Dosimetry System: TRDS-2016D code for reconstruction of deterministic estimates of dose from environmental exposures. Health Physics. 2019;117(4): 378-387.

16. Krestinina LYu, Kharyuzov YE, Epiphanova SB, Tolstykh EI, Deltour I, Sch z J, et al. Cancer Incidence after In Utero Exposure to Ionizing Radiation in Techa River Residents. Radiation Research. 2017;88(3): 314-324.

17. Glantz S. Primer of biostatistics: Translated from English. Moscow: Praktika; 1998. 459 p.

18. Shalaginov SA, Krestinina LYu, Startsev NV, Akleyev AV. Peculiarities of the resettlement of the first generation offspring of the exposed Techa River population. Radiatsionnaya Gygiena = Radiation Hygiene. 2017;10(2): 6-15 (In Russian)

19. James WH, Rostron J. Parental age, parity and sex ratio in births in England and Wales 1968-1977. Journal of Biosocial Sciences. 1985;17: 47-56.

20. Jacobsen R, Moller H, Mouritsen A. Natural variation in the human sex ratio. Human Reproduction. 1997;14(12): 3120-3125.