Age trend in the mortality from diseases of the circulatory system during the pandemic under a decrease in air pollution

Introduction. The results of large-scale studies of the mortality from diseases of the circulatory system (DCS) during the pandemic require further analysis of the data and the search for modifying factors. The purpose is to identify the features of the trend in the mortality from DCS in the population of an industrial center during a pandemic under changes in air pollution. Materials and methods. The research was carried out in the industrial center – Bratsk. Age-specific mortality rates were studied using exponential models in the background (2017) and pandemic (2021) periods. The contribution of atmospheric air pollution to the mortality rate was calculated in accordance with the “Guidelines for assessing the risk to public health from exposure to chemical substances that pollute the environment.” Results. The age-related increase in the mortality rate from DCS over 2017 was 125%, and during 2021 – 172%. During the pandemic, the excess mortality rate was in cases older 80 years – 35.92‰, 70–79 – 8.48‰, 60–69 – 1.03‰. PM10 levels in the air decreased from high to alarming levels in 2021, resulting in a reduction in excess PM10-related deaths from 194 (CI: 193.6–195.1) to 5.0 (CI: 4.8–5.1) cases. Limitations are associated with incomplete epidemiological knowledge about the dependence of mortality from DCS on exposure to air pollutants. Conclusion. The use of nonlinear regression analysis made it possible to demonstrate changes in trends in age-specific mortality during the background period and during the pandemic. During the pandemic, the level of excess mortality was revealed to relate with PM10 air pollution decreased.