Ecological Systems and Devices Annotation << Back The use of Information and Analytical Methods of Mathematical Statistics to Analyze the Dynamics of Mortality from Malignant Neoplasms of the Digestive System In the Territories of the Chelyabinsk Region Affected by Radiation Accidents Zhivoderov A.A., Konshina L.G. Studies conducted earlier using descriptive statistical methods have shown a significant increase in mortality rates from malignant neoplasms of the digestive system. The use of more informative methods of mathematical statistics allows us to obtain additional information, in particular on the impact on the mortality rate of emissions from various industrial enterprises. The study of mortality from malignant neoplasms of the digestive organs was carried out using methods of variance analysis, "odds ratio" and rank correlation. The observation time is divided into two periods: from 1950 to 1976 and from 1977 to 1996. Statistically significant excess mortality over the control level was established in all the studied territories, both during the period of active releases of radioactive substances by Mayak and after their cessation. According to the results of the analysis of variance and the "odds ratio" method, the same pattern is found – a decrease in indicators as you move away from the Mayak combine. The coefficients of the rank correlation of mortality with the distance of the territory from the Argayash thermal power plant are comparable with similar coefficients associated with the distance from the Mayak software. This indicates the comparability of the effect of emissions from the Mayak and Argayash thermal power plant on the occurrence of malignant neoplasms of the digestive organs both in the period before 1976 and after. The increase in mortality in the period 1950–1976 and its decrease in 1977–1996 is more significant in rural areas compared to cities. No significant influence of other factors on the mortality of the population was found. A uniform and synchronous decrease in mortality from malignant neoplasms of the digestive organs after 1976 was established without redistribution of ranking places between territories. The impact of Argayash CHPP emissions on mortality from malignant neoplasms of the digestive system turns out to be commensurate with the impact of Mayak emissions for most territories and population groups during the entire study period. Keywords: mortality; malignant neoplasms; analysis of variance; rank correlation; odds ratio. DOI: 10.25791/esip.8.2025.1540 Pp. 33-45.