## 4 Discussion
These resorts include Goczalkowice Zdroj, Konstancin, and Inowroclaw, located in close proximity to large cities. However, the air in most health resorts with this treatment profile has the lowest NO\({}_{2}\) levels. These resorts are located in mountainous areas, mainly in the Carpathians, namely Piwniczna, Polanczyk, Romanow, and Krynica Zdroj. Health resorts are most often frequented by elderly people suffering from various illnesses, hence the harmful impact of NO\({}_{2}\) is particularly strong in their case, particularly because health resorts with a high concentration of nitrogen dioxide also suffer from pollution with dust and other harmful substances [44]. Staying in areas with elevated nitrogen dioxide levels can have negative health effects. Ongoing research confirms the relationship between NO\({}_{2}\) in the air and the number of cancer deaths [9; 10; 12; 45]. Studies conducted in Poland also indicate the influence of the amount of pollution on the frequency of asthma attacks (hospitalisations) [46] or an increase in mortality linked to COVID-19 [47]. However, the studies conducted thus far have not been based on the satellite data, hence the need to undertake this type of research. In the absence of data on deaths and illnesses in tourist reception areas, it was not possible to accurately estimate the impact of elevated NO\({}_{2}\) concentrations on the health of their residents and visitors. We therefore conducted an assessment of the impact of NO\({}_{2}\) concentrations extracted from the satellite data for the entire country. Our analyses demonstrate the existence of a correlation between nitrogen dioxide content and the total number of deaths and the number of deaths from cancer (0.44 and 0.54). The correlation was particularly noticeable in the case of urban districts, with more than 150,000 inhabitants. Similar correlations between the number of deaths and NO\({}_{2}\) levels in the air were found by [PERSON] and [PERSON] [47] (\(\rho=0.60\), \(p<0.05\)) and by [PERSON] et al. [48] for deaths related to COVID-19 (R\({}^{2}\) = 0.319). The levels of air pollution can be an important factor in decisions about choosing particular tourist destinations [49; 50]. Increased pollution, particularly in cities, results in a reduction in the number of tourists visiting them [51; 52; 53]. The quality of the environment can thus have a direct impact on the economy in addition to its effects on health. Therefore, this factor should be taken into account by policymakers. In the case of Polish tourists, however, the researchers highlight the discrepancy between declarations about the significant impact of air quality on the choice of travel destinations and the actual awareness of pollution levels [50]. The standards for NO\({}_{2}\) content in the air currently applicable in the Polish legal system are clearly higher than those suggested by the WHO. In addition, in both cases, they rely on  
Figure 7: Relation of NO\({}_{2}\) monthly concentrations in 2020 to 2019.  
units different from those obtained from the satellite measurements. Therefore, for the time being, it is impossible to take concrete action based on such results. However, they provide important information on the spatial variation in NO\({}_{2}\) content and indicate potentially vulnerable areas where further research, including ground-based monitoring, should be carried out. The use of satellite data opens up another chapter of research into the state of pollution, including in areas that have not been covered by monitoring to date due to the lack of ground-based measurement stations. It is also possible to study the impact of local conditions on the amount of pollution and its migration routes. With point measurements, this was not possible. The data obtained enables better management of the environmental condition in tourist reception areas and takes action where NO\({}_{2}\) pollution levels exceed acceptable standards. These may primarily concern measures to reduce the volume of automobile traffic.