Medical Radiology and Radiation Safety. 2014. Vol. 59. No. 6. P. 24-33
RADIATION MEDICINE
T.V. Azizova1, G.V. Zhuntova1, M.B. Moseeva1, E.S. Grigoryeva1, M.V. Bannikova1, Z.D. Belyaeva1, E.V. Bragin1, R. G. E. Haylock2, N. Hunter2
Risk of chronic bronchitis Incidence in the cohort of Mayak PA Nuclear Workers
1. Southern Urals Biophysics Institute of the FMBA of Russia, Ozyorsk, Chelyabinsk region. E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it. ; 2. Public Health of England, Chilton, United Kingdom
ABSTRACT
Purpose: To assess risk of chronic bronchitis incidence (CB) in Mayak workers cohort accounting for radiation (total external gamma-rays, internal alpha-radiation from incorporated plutonium) and non-radiation factors.
Material and methods: Mayak workers cohort consists of 12210 workers, employed at radiochemical or plutonium production plant from 1948 to 1958. The analysis included 1175 CB cases verified retrospectively based on medical records. Mean total absorbed dose from external gamma-rays to lung (± standard deviation, SD) for the entire follow-up was 0.7±0.9 Gy in males and 0.5±0.7 Gy in females; mean total absorbed dose from internal alpha-radiation to lung was 0.2±0.9 Gy in males and 0.6±2.9 Gy in females. Poisson regression methods were applied to assess relative risk (RR) and 95 % confidence interval (95 % CI) using the AMFIT module of EPICURE. Excess relative risk (ERR/Gy) estimates were calculated using linear dose-response.
Results: Occupational exposure was found to affect CB incidence in Mayak workers. The analysis adjusted for non-radiation factors including smoking has shown statistically significant increase in RR of CB incidence at total absorbed dose from internal alpha-radiation to lung more than 0.1 Gy; ERR/Gy was 1.11 (0.43–2.20)/Gy. External gamma irradiation has shown to affect less distinct: ERR/Gy was 0.14 (0.01–0.32)/Gy of total absorbed gamma-dose to lung, however, categorical analysis shown no statistically significant increase in RR. CB incidence risk among Mayak workers, as well as, in general population increased with attained age and was associated with smoking. Steep increase in CB incidence among Mayak workers before 1960 is to be explained further. Radiation risk estimates for CB incidence are to be clarified further using multivariate analysis with the extended follow-up period, quantitative smoking characteristics and characteristics of industrial aerosols.
Key words: chronic bronchitis, smoking, external gamma-irradiation, internal alpha-irradiation, Mayak PA