Assessment of health risks caused by respiratory diseases upon exposure to ambient air pollution during heat waves in Perm region

Introduction. Growing human impacts on the environment together with ongoing climate change make provision of sanitary-epidemiological wellbeing of the population a truly vital issue. Health risks associated with chemical ambient air pollution and caused by respiratory diseases can grow during heat waves, among other things, due to greater susceptibility of the respiratory system to chemical exposures.The aim of this study was to quantify respiratory health risks upon exposure to chemical ambient air pollution during heat waves in an industrially developed region (the Perm region) used as an example.Materials and methods. Likelihood of respiratory diseases was calculated by using logistic regression models. The calculations were based on the following indicators: average daily air temperatures (abnormally warm days), depersonalized incidence rates, and average daily concentrations of chemicals in ambient air in cities in the Perm region.Results. Risk levels caused by exacerbated asthma and chronic bronchitis among the regional population and associated with such ambient air pollutants as nitrogen oxide, xylenes, and sulfur dioxide were found to be higher during heat waves against their levels without allowing for abnormally warm days. When chemical levels are below MPC in ambient air, the risks are within their acceptable ranges and a period, during which they grow up to unacceptable levels, is between 5 and 22 abnormally warm days depending on a chemical and age group. When chemical levels grow up to MPC, health risks become unacceptable over a period from 1 to 16 abnormally warm days.Limitations. Logistic regression models were built using data on settlements in only one region of the Russian Federation (the Perm region).Conclusion. Ambient air pollution during heat waves creates elevated health risks caused by exacerbation of respiratory diseases. This should be considered when developing preventive activities within programs for population adaptation to climate change.Compliance with ethical standards. The study did not require approval by the local ethics committee (it was accomplished using data provided by the regional office of the Mandatory Medical Insurance Fund).Contributions: Zaitseva N.V. – study concept and design, Editing the text; Shur P.Z. – study concept and design, Editing the text; Khasanova А.А. – data collection and analysis, writing and editing the text, mathematical data analysis; Chigvintsev V.М. – mathematical data analysis. All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.Conflict of interest. The authors declare no conflict of interest.Funding. The study had no sponsorship.Received: October 22, 2025 / Accepted: December 2, 2025 / Published: January 15, 2026