Ambient Gaseous Pollutants and Circulatory-System Morbidity in Four Industrial Settlements of East Kazakhstan: A Trend-Sensitive Ecological Analysis, 2014–2024

The industrial settlements of East Kazakhstan have long been exposed to ambient air-pollution pressure, yet the association between gaseous pollutants and cardiovascular morbidity in the region’s population remains insufficiently studied. This study aimed to assess the association between ambient air pollution and the primary incidence of circulatory system diseases in the population of the industrial settlements of East Kazakhstan (Ust-Kamenogorsk, Ridder, Glubokoe, and Altai) over the period 2014–2024. A retrospective ecological analysis of annual data on H2S, SO2, CO, NO2, the API5, and primary incidence of circulatory-system diseases (CSD) was conducted. Associations were assessed using Spearman correlation with FDR correction, lag analysis, and partial rank correlation controlling for the calendar year. After FDR correction, nine comparisons retained statistical significance, all in Ridder, corresponding to six exposure–outcome combinations (ρ = −0.718 to −0.828; q = 0.020–0.0498). After controlling for the calendar year, none of these comparisons remained statistically significant. The lag analysis at shifts of 1–3 years likewise revealed no associations that retained significance after FDR correction. The associations identified were sensitive to the overall temporal trend. The results do not confirm a robust independent or delayed association between the air pollution indicators studied and primary cardiovascular morbidity within the framework of the aggregated annual data; they do not, however, exclude an adverse effect that a larger study with higher temporal resolution might detect.