Tritium in the urine of the Mayak PA workers in the period from 2017 to 2019

Objectives. To define the levels of volume activity of tritium compounds and fraction of organically bound tritium in urine of chemical production workers of “Mayak Production Association” in present-day conditions; to identify the relationship between volume activity levels and professional occupation (department and profession). Material and methods. 245 urine samples from 171 workers of Mayak Production Association tritium production facility were collected in the period from 2017 to 2019. Volume activity of tritium compounds was measured by liquid scintillation method using spectrometer Quantulus-1220. The samples were distilled or dried and then combusted using an automatic preparation and oxidization system Sample Oxidizer A307. The “R” software was used for statistical analysis and for processing the measurement results and occupational factors. Chaddok’s scale was applied to determine the degree of correlation. The significance level was taken equal to 5%. Results. The value of total tritium volume activity in the urine and tritium volume activity in the water phase varied within 4 orders of magnitude (from ~30 Bq/dm³ to ~250 kBq/dm³). The value of volume activity of organically bound tritium in the urine varied within 2 orders of magnitude (from ~6 Bq/dm³ to ~3000 kBq/dm³). The fraction of organically bound tritium in the urine of the workers was within the range from 0,07% to 74%, and did not differ statistically significantly from lognormal distribution with parameters GM=2,7% and GSD=3,7. Very high rank correlation was detected between total volume activity of tritium compounds and tritium volume activity in the water phase in the urine. Noticeable rank correlations were detected between the total volume activity of tritium compounds in the urine and volume activity of organically bound tritium, as well as between tritium volume activity in the water phase and volume activity of organically bound tritium in the urine. The total tritium volume activity and tritium volume activity in the water phase in the urine of the workers of the 1st department and of the analytical laboratory of Mayak Production Association tritium production facility were statistically significantly higher than in the workers of the 2nd department according to median values. Statistically significant differences between medians of the total tritium volume activity in the urine and tritium volume activity in the water phase related to profession were observed only in the workers in the 1st department. Conclusion. Estimation of tritium volume activity in the water phase by the level of total tritium volume activity in the urine without sample preparation is possible with 95% reliability within limits of one order of magnitude towards the model value. Estimation of volume activity of organically bound tritium in the urine without sample preparation by the level of total tritium volume activity in the urine without sample preparation is possible with 95% reliability within limits of two orders of magnitude towards the model value. The effect of occupational factors to the levels of volume activity of tritium compounds in the urine of Mayak Production Association professional workers was detected.

1. Butler HL, Leroy JH. Оbservation of biological half-life of tritium. Health Physics. 1965 Apr;11: 283–5.

2. Hamra G, Nylander-French LA, Richardson D. Dose reconstruction for an occupational cohort at the Savannah River nuclear facility: evaluation of a hybrid method. Radiation Protection Dosimetry. 2008;131(2): 188–97.

3. Little MP, Wakeford R. Systematic review of epidemiological studies of exposure to tritium. Journal of Radiological Protection. 2008 Mar; 28(1): 9–32.

4. Novoselov VN. Extending plutonium and tritium production capacities at Mayak PA in the cold war (1948-1950-ies). Sotsium I Vlast = Society and Authority. 2012;3(35): 121-123. (In Russian).

5. Kruglov A. The History of the Soviet Atomic Industry. CRC Press; 2002.

6. Kiselev G, Tkach K. Lithium, deuterium and tritium for the hydrogen bomb. Byulleten po atomnoy energii = Atomic energy report. 2004;(11): 70–6. (In Russian).

7. Novoselov VN, Nosach YuF, Entyakov BN. Atomic heart of Russia. Chelyabinsk: Authograph; 2014. 528 p. (In Russian).

8. Trivedi A, Duong T, Leon JW, Linauskas SH. Measurement of organically bound tritium in urine and feces. Atomic Energy of Canada Limited; 1993. 29 p.

9. Gonen R, Marco R, German U, Katorza E, Alfassi ZB, Haquin G, et al. An improved method for Organic Bound Tritium (OBT) determination in urine samples. Radiation Protection Dosimetry. 2007 Jul 1;125(1–4): 460–4.

10. Galeriu D, Takeda H, Melintescu A, Trivedi A. Energy Metabolism and Human Dosimetry of Tritium. Fusion Science and Technology. 2005; 48(1):795–8.

11. Galeriu D, Melintescu A, Beresford NA, Takeda H, Crout NMJ. The dynamic transfer of 3H and 14C in mammals: a proposed generic model. Radiation and Environmental Biophysics. 2009 Feb;48(1): 29–45.

12. Galeriu D, Melintescu A. Retention of tritium in reference persons: a metabolic model. Derivation of parameters and application of the model to the general public and to workers. Journal of Radiological Protection. 2010 Sep;30(3): 445–68.

13. Richardson RB, Dunford DW. A biochemical-based model for the dosimetry of dietary organically bound tritium--Part 1: Physiological criteria. Health Physics. 2003 Nov;85(5): 523–38.

14. Richardson RB, Dunford DW. A biochemical-based model for the dosimetry of dietary organically bound tritium-Part 2: Dosimetric evaluation. Health Physics. 2003 Nov;85(5): 539–52.

15. Trivedi A, Galeriu D, Richardson RB. Dose contribution from metabolized organically bound tritium after acute tritiated water intakes in humans. Health Physics. 1997 Oct;73(4): 579–86.

16. Trivedi A, Galeriu D, Lamothe ES. Dose contribution from metabolized organically bound tritium after chronic tritiated water intakes in humans. Health Physics. 2000 Jan;78(1): 2–7.

17. Balonov MI, Chipiga LA. Estimation of the dose from tritium oxide intake in human body: the role of inclusion of tritium into organic compound of the tissues. Radiatsionnaya Gygiena = Radiation Hygiene 2016;9(4): 16–25. (In Russian).

18. United Nations, Scientific Committee on the Effects of Atomic Radiation Sources, effects and risks of ionizing radiation: UNSCEAR 2016 report to the General Assembly, with scientific annexes. Sources, effects and risks of ionizing radiation. 2017.