Abstract
This study analyzes air pollution by fine particulate matter (PM2.5) in Almaty, the largest megacity of Kazakhstan. The city is located in a basin formed by the spurs of the Zailiyskiy Alatau range. Due to its geographical features, it is highly exposed to pollution by anthropogenic fine particulate matter. The main sources of air pollution include transport, industrial enterprises, and heating systems. The objectives of this study are to identify the dominant source of pollution, to assess spatial heterogeneity between central and foothill districts, and to evaluate the effectiveness of household air purifiers in improving indoor air quality. Urban vehicular traffic exhibits a periodic temporal pattern, with daily minima at night and weekly minima on weekends. This dynamic behavior enables a quantitative assessment of its contribution to the overall PM2.5 concentration in the urban atmosphere. The results suggest that heat generation systems are likely to be the dominant contributor to PM2.5 pollution during the autumn–winter period. In addition, observations indicate that high pollution levels in foothill areas occur approximately 30% less frequently than in central districts. The use of household air purification systems may reduce indoor particulate matter concentrations severalfold under the observed conditions.