Solid cancer incidence among emergency workers of the Chernobyl accident: assessment of radiation risks for the follow-up period of 1992-2009

The cancer among emergency workers of the Chernobyl accident for the follow-up period of 1992-2009 is analyzed in the article. The cohort consists of 67,568 emergency workers of 1986-1987. Mean dose in emergency workers is 132 mGy. Over the period of 1992-2009 a total of 4,002 solid cancers of different sites were diagnosed in the study cohort. The statistically significant increase by 18% in the incidence rates for all solid cancers in the emergency workers was detected in comparison with the background incidence in the male population of Russia (SIR=1.18, 95% CI: 1.15; 1.22). As for the malignant neoplasms of respiratory system, the average incidence rate was 27%, it is significantly higher than in men of Russia (SIR=1.27, 95% CI: 1.19; 1.34). Radiation risk for cancer incidence [excess relative risk per unit dose 1 Gy (ERR Gy -1) is 0.47; 95% confidence interval (CI): 0.03; 0.96, p-value=0.034)] is found to be statistically significant. The obtained results are preliminary, further epidemiological studies are necessary.