The aim of this study was to expand the monitoring network and evaluate the accuracy of inexpensive WoMaster ES-104 sensors for monitoring particulate matter (PM) in temperate latitudes, using the example of the Southern Baikal region. The research methods included continuous measurements of PM_2.5 and PM₁₀ concentrations, temperature, and humidity at three stations (Listvyanka, Patrony, and Tankhoy) from October 2023 to October 2024, using the LCS WoMaster ES-104. ERA5-Land reanalysis data and the HYSPLIT model were used to analyze meteorological conditions and air mass trajectories. The results of this study showed a high correlation between the WoMaster ES-104 and the DustTrak 8533; the correlation coefficient was 0.94 (R² = 0.85) for both fractions. The seasonal dynamics of PM_2.5 and PM₁₀ were characterized by a dual-mode distribution with maxima in summer (secondary aerosols, high humidity) and winter (anthropogenic emissions, inversions). The diurnal cycles showed morning/evening peaks associated with transport activity and atmospheric stratification. Extreme concentrations were recorded in anticyclonal weather (weak north-westerly winds, stable atmosphere). This study confirms the suitability of the LCS WoMaster ES-104 for real-time monitoring of PM_2.5 and PM₁₀, which contributes to sustainable development by increasing the availability of air quality data for ecologically significant regions such as Lake Baikal.

The paper presents the results of synchronous measurements of the content of small gas impurities at the three atmospheric monitoring stations located on the shore of Southern Baikal, July 2023. The measurements were carried out using automatic gas analyzers, which enabled to obtain data on the content of sulfur and nitrogen oxides in the atmospheric air with high temporal resolution. The studies showed that in spite of a small distance between the observation stations, the fluctuations of concentrations of small gas impurities on different shores of Southern Baikal occur independently of each other. We suggested that an increase of nitrogen and sulfur oxide concentrations on the western shore in summer is probably correlated more with the impact of regional thermal power plants (TPP) and on the eastern shore with the orographic features of the southern basin of the lake and local sources. The influence of meteorological conditions on the content of gas components in the atmosphere of Southern Baikal was estimated using multivariate statistical methods, namely, NWR and PSCF.

Lake Baikal is a UNESCO World Heritage Site and the largest freshwater reservoir on the planet. It is located in the center of Eurasia, in an industrially developing region—Eastern Siberia. Although a regulatory and legal framework exists, quantitative estimates of the pathways of pollutant transport from industrial sources to the lake water area remain insufficiently studied, particularly in the context of seasonal dynamics and the influence of developing industrial sectors. In the present work, a quantitative analysis of the direct atmospheric transport of pollutants from three groups of stationary sources (the Irkutsk agglomeration, the Republic of Buryatia, and the oil-and-gas production areas of Irkutsk Oblast) to the lake surface was carried out for the first time using the HYSPLIT model for the period 2005–2025. About 4.7 million forward trajectories were computed at three heights (250, 500, 1000 m AGL) for each group of sources. It was established that conditions favorable for the transport of impurities to the lake occur in more than half of the cases. However, the spatial distribution of the impact on the Baikal air basin is heterogeneous: the Irkutsk agglomeration accounts for 67.5% of the “hits” (the main contribution being to the air basin of the Southern Basin), the Republic of Buryatia 18.8% (to the Central Basin), and the oil-and-gas areas 19.9% (to the Northern Basin). On the basis of a multifactor analysis, a combined Potential Impact (PI) index was developed that makes it possible to rank regional sources by the degree of their impact on the lake ecosystem, taking into account the emission volume, the probability of delivery, the residence time, and the height of trajectory passage. The results form a scientific basis for optimizing the spatial placement of environmental monitoring networks and for preliminary zoning of environmental risk assessment over the Lake Baikal water area. Ultimately, this study contributes to the sustainable management of the Baikal Natural Territory by providing actionable insights for balancing regional industrial growth with the long-term ecological preservation of the planet’s largest freshwater reservoir.