Spatiotemporal Associations Between Ambient Air Pollution and Neoplasm Morbidity in Eastern Kazakhstan: Age-Specific Patterns and Spatial Heterogeneity, 2014–2024

Industrial settlements of the East Kazakhstan Region face a persistent technogenic burden driven by the dense concentration of non-ferrous metallurgy and heat-and-power enterprises, further compounded by unfavorable pollutant dispersion conditions inherent to the region’s mountain–basin topography. This study evaluated spatiotemporal associations between annual mean concentrations of NO2, SO2, H2S, and CO, the integrated air pollution index (API5), and primary neoplasm morbidity across five settlements over the period 2014–2024. A retrospective ecological analysis was carried out for Ust-Kamenogorsk, Ridder, Altai, Shemonaikha, and the settlement of Glubokoe, incorporating Spearman’s rank correlation, lag analysis (1–3 years), and the Mann–Kendall trend test. Throughout the study period, neoplasm morbidity in the region consistently exceeded the national average by a factor of 1.3 to 2.0. In Ust-Kamenogorsk—where metallurgical SO2 and NO2 emissions are most heavily concentrated—strong positive associations were found in children for SO2 (ρ = 0.791, p < 0.05) and in adolescents for NO2 and CO, reflecting elevated inhalation exposure under conditions of chronic pollution. The negative associations with API5 observed in Ridder and Altai, where the index showed a statistically significant downward trend, are interpreted as evidence of the inertial character of oncological processes and the lasting influence of cumulative past exposure. Across all studied settlements, SO2 emerged as the most consistent predictor of morbidity variation. These findings support prioritizing stricter emission controls for SO2 and NO2 from metallurgical and energy facilities, establishing oncological screening programs for children and adolescents in chronically polluted areas, and strengthening ambient air monitoring—measures whose effective implementation will require coordinated action between public health authorities and environmental regulators.