## 5 Conclusions  
This study was conducted to characterize the composition of PAHs present in snow. The developed method, compared to standard atmospheric pollution assessment techniques, is cost-effective (e.g., Radiello air passive sampler cost of USD 350 per unit), user-friendly (in terms of sampling, accessibility, and minimal matrix interferences), and serves as a relatively reliable indirect alternative for assessing air quality during the winter season when snow cover is present. Furthermore, the proposed procedure allows for the simultaneous measurement of atmospheric pollution and the subsequent transfer of contaminants into soil and groundwater. However, when using snow cover as a deposition medium, special precautions must be taken, as pollutant concentrations and source identification are highly dependent on weather conditions. To ensure sample homogeneity and prevent analyte loss, sampling should be conducted immediately after fresh snowfall and under stable weather conditions (i.e., windless conditions and temperatures below 0 \({}^{\circ}\)C). In the analytical phase of the study, the application of solid-phase extraction for concentration and purification, a specialized high-resolution PAH column, pulsed injection, and the dMRM GC-MS/MS mode resulted in low limits of detection and quantification. This approach enabled the detection and quantification of all 16 PAHs in each sample. This represents a significant advantage of the developed method, as most previous studies have reported incomplete results for PAHs in snow samples due to concentrations falling below the LOD of the applied analytical techniques.  
The studied village, characterized by its mountainous location, low population density, extensive forest cover (66% of the municipality area) [42], and the absence of large industrial facilities in the vicinity, would be expected to exhibit minimal environmental contamination. However, analysis of polycyclic aromatic hydrocarbons in the snow cover revealed relatively high levels of contamination, particularly from high molecular weight (HMW) PAHs, comparable to those observed in urban areas. Notably, higher PAH concentrations did not necessarily coincide with the areas most exposed to traffic, tourism, or the highest population density. This suggests that topographical features and vegetation cover play a significant role in the deposition of PAHs. Diagnostic ratio analysis indicated that the predominant source of PAHs is pyrogenic, primarily originating from biomass and coal combustion. This finding aligns with data provided by the mayor of the municipality [42],who reported that the majority of households rely on solid fuels, including coal, wood, and other forms of biomass, for heating. Additionally, areas with higher visitor traffic exhibited an increased contribution of petroleum-derived PAHs, likely from vehicle emissions. An attempt was made to assess the potential environmental and biological risks associated with the detected PAH concentrations and their distribution. The calculated toxicity (BaP\({}_{\text{TEQ}}\)), mutagenicity (BaP\({}_{\text{MEQ}}\)) coefficients, and risk quotient (RQ) values indicated alarming pollution levels. These findings warrant attention from local authorities to implement measures aimed at improving environmental quality.  
Conceptualization, K.W.; Data curation, K.W.; Funding acquisition, K.W. and W.Z.; Investigation, K.W., G.B.-P. and I.L.; Methodology, K.W., W.Z. and I.L.; Project administration, K.W.; Resources, K.W.; Supervision, K.W.; Validation, K.W. and W.Z.; Visualization, K.W. and G.B.-P.; Writing--original draft, K.W. and W.Z.; Writing--review & editing, K.W. and G.B.-P. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
Dataset available on request from the authors.  
The authors declare no conflicts of interest.