AIR TEMPERATURE AND OZONE CONCENTRATION AS RISK FACTORS FOR LIFE-THREATENING CARDIOVASCULAR CONDITIONS IN SOUTHERN RUSSIA

Abstract

Heat waves and increasing tropospheric ozone concentration accompanying global warming are recognized as risk factors for public health. The aim of the study was to assess the associations between atmospheric air temperature, ozone concentration as risk factors for life-threatening cardiovascular conditions in Southern Russia. Methods. An ecological study was performed. The number of ambulance calls (the monthly average for 2017 and daily for January, April, July and October) for acute cerebrovascular conditions, hypertensive crises, and acute myocardial infarction were analyzed. Data on mean daily air temperature was obtained from the weather reports (https://rp5. ru). The ozone concentration was determined by the optical method using an automatic gas analyzer at the environmental monitoring station in the Karadagsky State Nature Reserve. Spearman nonparametric correlation analysis was applied to study associations between the outcomes and the selected environmental conditions. Results. During 2017, the average daily concentration of ozone in the surface layer of the atmosphere exceeded the norm by 50-150 %s. The largest number of significant correlations between all recorded cardiovascular life-threatening conditions and air temperature and ozone concentration was detected in July (0,38 < rs < 0,79; all p-values < 0,05). In other seasons of the year, this correlation was somewhat weaker (0,43 < rs < 0,47; all p-values < 0,05). Associations between hypertensive crises and myocardial infarction and average daily temperature were found in January. An association between myocardial infarction and the surface ozone concentration was observed in October. Conclusion. The maximum number of emergency conditions occurring in the summer months may be associated with the synergistic effects of of high levels of ozone and air temperature.