## 2 Study Area  
The study was carried out in Zawoja village (49\({}^{\circ}\)34\({}^{\prime}\)19.74\({}^{\prime\prime}\); 19\({}^{\circ}\)28\({}^{\prime}\)2.568\({}^{\prime\prime}\) to 49\({}^{\circ}\)41\({}^{\prime}\)55.428\({}^{\prime\prime}\) 19\({}^{\circ}\)37\({}^{\prime\prime}\)9.3\({}^{\prime\prime}\)) in southern Poland, near the border with Slovakia (Figure 2). Zawoja is the largest and the longest village in Poland, located at the foothills of Babia Gora Mountain, which encompasses the highest peak (Diablak, 1725 m asl) of the Polish Beskidy Mountain Range. The Babia Gora Massif is protected by Babia Gora National Park. Zawoja stretches for 18 km and covers an area of 128 km\({}^{2}\)[41], diversified in terms of topography, spatial development, and economic and tourist activities. The village's altitude ranges from 426 m asl to the summit of Babia Gora at 1725 m asl. The Municipality of Zawoja, as of 31 st December 2023 was inhabited by 8855 people [42]. The village is a popular tourist destination, serving as the gateway to Babia Gora hiking trails, and in recent years, the number of visitors entering Babia Gora National Park exceeded 100,000 people annually [43].  
The climate in Zawoja is classified as humid continental (Dfb) according to the Koppen-Geiger classification [44; 45]. The local climate was characterized using data from 1989 to 2018, recorded by the meteorological station in Zawoja (697 m asl), operated by the Institute of Meteorology and Water Management--National Research Institute (IMGW-PIB). The  
Figure 2: Location of study area and sampling sites. Map created using Open Source software QGIS 3.34 Prizren.  
average annual air temperature during this period was 6.7 \({}^{\circ}\)C, with a maximum of 8.2 \({}^{\circ}\)C in 2014 and a minimum of 4.8 \({}^{\circ}\)C in 1996. Annual precipitation averaged 1262.4 mm, ranging from 917.3 mm in 1993 to 1796.3 mm in 2010. Snow cover was present for an average of 90 days per year, with extremes of 24 days in 2014 and 120 days in 2005. Compared to the 1961-2015 period [46], this data indicates a slight increase in the average temperature (previously 6.4 \({}^{\circ}\)C) and a decrease in snow cover duration (previously 104 days). Wind simulation from the Global Wind Atlas, based on a 10-year mesoscale dataset (2008-2017) from the European Centre for Medium-Range Weather Forecasts (ECMWF), shows that winds predominantly come from the west-southwest (W-SW) direction (Figure 3) and during winter months reach an average speed of 1 m/s [47]. The atmosphere in this area is particularly exposed to PAH emissions from various sources, including coal and biomass combustion, tourist activities with the use of numerous ski lifts or mountain hiking trails, and local businesses, such as the wood and furniture industry. During the winter season, the main factor contributing to increased exposure to pollutants, including PAHs, is household heating. According to the 2023 report from the Central Building Emissions Register (Centralna Evidencja Emisyinosci Budynkow--CEEB), the following heat sources were identified in the municipality of Zawoja: solid fuels (coal, wood, pellets, or other types of biomass)--4079; other sources (oil heating, electric heating, district heating, system heat)--1308; renewable energy sources (heat pumps for space heating and domestic hot water, solar collectors)--1002; gas--72 [42]. This indicates that the dominant source of heating in the studied village is the combustion of solid fuels. The dominant heating device for solid fuel combustion was a solid fuel boiler (-50%), then a wood stove (-25%).