Background: According to the World Health Organization (WHO), air pollution was responsible for 8.1 million deaths globally in 2021, making it the second leading cause of death, including among children under 5 years old. Air pollution is also linked to a range of diseases such as stroke, chronic obstructive pulmonary disease, lung cancer, and asthma. In Ulaanbaatar, the capital of Mongolia, the average daily concentration of PM2.5 particles in the air reaches 750 μg/m3 during winter, which is 50 times higher than the WHO’s recommendation, making it one of the most polluted cities in the world. Air pollution continues to pose a significant public health challenge not only in Mongolia but also in many countries globally. However, there is a lack of comprehensive research and studies that summarize and review the existing work in this field. Aim: To summarize and review thematic works on air pollution conducted by researchers from Mongolian universities. Materials and Methods: A systematic review and analysis were performed on thematic works by researchers who completed their master’s and doctoral degrees in the field of air pollution between 2011 and 2024. Results: In terms of the type of master’s and doctoral dissertations, 76.0% (n=19) were master’s theses and 24.0% (n=6) were doctoral dissertations. Among the total number of works included in the study, 36.0% (n=9) focused on the health effects of air pollution, while 64.0% (n=16) addressed other related areas. Some studies indicated that PM2.5 levels in the air between 2011 and 2024 were 1-6 times higher than the Mongolian standard, with the highest levels observed from November to February and the lowest in July. Additionally, some studies suggested a reduction in PM2.5 levels following the introduction of improved fuel in Ulaanbaatar. Air pollution was found to increase the risk of respiratory and cardiovascular diseases, as well as cancer, and to contribute to reduced fetal weight. Conclusion When examining thematic studies on air pollution conducted by state-owned universities in Mongolia, the primary focus has been on the composition, concentration, and health impacts of air pollution. Going forward, research aimed at mitigating air pollution should be driven by collaborative efforts and leadership from universities, with the results being effectively communicated to policymakers.

Background: Particulate matter in ambient air is an important risk factor for cardiovascular and respiratory diseases. Accurate and appropriate air quality monitoring is therefore critical for public health. In this context, it is necessary to investigate the feasibility of using low-cost direct monitoring devices (such as PurpleAir) in outdoor environments during the winter season, particularly in urban areas where fixed monitoring stations are not available. Aim: To assess and compare the outdoor PM2.5 concentrations in Ulaanbaatar and Darkhan during the winter season. Materials and Methods: The study was conducted in the capital city of Mongolia. The data collected for 45 days during the winter season, from December 9, 2024 to February 14, 2025. Continuous low-cost sensor was collected using a light scattering device (PurpleAir Classic) at a total of 25 locations and for 24 hours. Of these, 1 location was located next to a fixed measurement point and 3 locations (Zuun 4 zam, Yarmag, Selbe) were located within 200m of the study area, and the measurement results were compared using PM2.5. We used R software for statistical analysis. Results: The average PM2.5 concentration measured at the 13 fixed monitoring sites during the study period was 65 μg/ m³, while the average from the 25 PurpleAir sensors was 88 μg/m³. Parallel measurements conducted with the PurpleAir sensors and the UB4 fixed monitoring station showed a moderate correlation (r=0.44, R²=0.22, p<0.05). The measurement results at the Zuun 4 zam, Yarmag, and Selbe locations have a moderate correlation (r=0.38, r=0.61, r=0.25). Conclusion In situations where it is not possible to measure PM2.5 particulate matter in outdoor air automatically or by conventional methods, it is possible to monitor air quality by measured by low-cost sensors.

Backgroun: Air pollution is a major global public health concern that poses serious risks to human health regardless of a country’s level of economic or technological development. According to the World Health Organization (WHO, 2021), nine out of ten people worldwide breathe polluted air, and air pollution is responsible for the deaths of approximately 800 people every hour and 13 people every minute. Prolonged exposure to polluted air has been linked to a wide range of chronic illnesses, including chronic obstructive pulmonary disease (COPD), lung and bronchial cancers, asthma, and stroke. In Mongolia, air pollution reaches its highest levels during the winter months, particularly in Ulaanbaatar, where the majority of the country’s population resides. A study conducted by Enkhjargal G. (2012) reported that the concentrations of PM10 and PM2.5 in Ulaanbaatar were 7–8 times higher than the WHO recommended guidelines. In response to such challenges, many countries have increasingly adopted low-cost, direct measurement devices such as PurpleAir to monitor air quality. These devices are valued for their accessibility, network connectivity, and potential role in smart city pollution management systems. Despite their global application, there remains a lack of research in Mongolia on the use of PurpleAir sensors to measure PM2.5 concentrations and compare the results with official monitoring station data. Addressing this gap is essential for improving local air quality monitoring capacity and informing effective public health and environmental policies. Aim: Determination of PM2.5 particulate matter pollution in the outdoor environment of Ulaanbaatar city using a direct measurement device (Purple Air). Materials and Methods: A cross-sectional study design was employed. Direct measurement devices (Purple Air) were installed in selected districts of central Ulaanbaatar between December 2024 and February 2025, measuring PM2.5 concentrations at two-minute intervals over 24-hour periods. All data were statistically processed and analyzed using the SPSS-26 software package. Results: The average concentration of PM2.5 particles in the air of Ulaanbaatar city in winter is 66.68 μg/m3. Compared to the districts, the highest concentration was determined in SKHD (118.58±90.22 μg/m3), while the lowest concentration was determined in KHUD (42.37±43.51 μg/m3). Compared to the days of the week, the highest concentrations were measured on Monday (76.68±71.98 μg/m³), Saturday (77.50±71.63 μg/m³), and Sunday (80.34±74.45 μg/m³). The highest concentration of PM2.5 particles occurred from 6 pm to 1 am, and the lowest concentration was measured during the day (between 2 pm and 4 pm). The highest concentration of PM2.5 was measured in December (74.22±73.45 μg/m3), while the lowest concentration was measured in February (50.25±57.44 μg/m3). Conclusion The concentration of PM2.5 in the air of Ulaanbaatar city is 1.7 times higher than the general standard and technical requirements of Mongolia in winter, and the highest concentration is in the SKHD. The highest concentration of PM2.5 occurs more often in December and at night than in the winter months.