## 3 Results
The toluene concentrations outside the shop in the cold months (December-March; 2.72 \(\pm\) 0.20 \(\upmu\)g/m\({}^{3}\)) were higher than in the warm period (0.89 \(\pm\) 0.19 \(\upmu\)g/m\({}^{3}\)). Regarding the concentration of toluene in the different departments, there was a variation between months (\(p\) < 0.05, 2-way ANOVA) but small statistical differences between departments ((\(p\) = 0.029, 2-way ANOVA). In the case of benzene (Figure 4B), the annual concentration in the sweets department was 6.2 \(\pm\) 2.9 \(\upmu\)g/m\({}^{3}\), in the detergents department was 5.79 \(\pm\) 2.1 \(\upmu\)g/m\({}^{3}\), and in the plastics department was 6.1 \(\pm\) 2.1 \(\upmu\)g/m\({}^{3}\). The annual average outdoor benzene concentration was 1.05 \(\pm\) 0.32 \(\upmu\)g/m\({}^{3}\). The highest benzene concentration was found in the sweets department in February 2021 at a level of 10.3 \(\pm\) 0.1 \(\upmu\)g/m\({}^{3}\) while the lowest was found in July at 1.99 \(\pm\) 0.05 \(\upmu\)g/m\({}^{3}\). Even more, benzene concentrations in different departments vary a lot across the year. Figure 4: Monthly variations in toluene (**A**), benzene (**B**), xylene (**C**), and monoterpene (**D**) concentrations over one-year measurements in 3 different departments and outside. Data with distinct characters indicate significant differences (\(p\) < 0.05), whereas data sharing identical symbols do not exhibit significant differences (\(p\) > 0.05). The annual average xylene concentration (Figure 4C) in the sweets department was 60.7 \(\pm\) 20.7 \(\upmu\)g/m\({}^{3}\), in the detergents department was 49.4 \(\pm\) 15.9 \(\upmu\)g/m\({}^{3}\), and in the plastics department was 56.0 \(\pm\) 15.2 \(\upmu\)g/m\({}^{3}\). For almost all months, the concentration of xylene was higher in the sweets department than in the detergents and plastics departments (_p_ < 0.05). The concentration of xylene outside was between 4.77 \(\pm\) 0.48 \(\upmu\)g/m\({}^{3}\) in July and 8.65 \(\pm\) 0.62 \(\upmu\)g/m\({}^{3}\) in January. The annual average monoterpene concentration (Figure 4D) in the sweets department was 88.3 \(\pm\) 14.7 \(\upmu\)g/m\({}^{3}\), in the detergents department was 88.99 \(\pm\) 4.8 \(\upmu\)g/m\({}^{3}\), and in the plastics department was 86.8 \(\pm\) 4.5 \(\upmu\)g/m\({}^{3}\). There is no difference between the monoterpene concentration in different departments (2-way ANOVA, \(p\) = 0.164), but there are significant differences between months (2-way ANOVA, \(p\) < 0.05). Furthermore, the highest concentrations of monoterrenes were found in April and May in the sweets departments (120.9 \(\pm\) 4.2 \(\upmu\)g/m\({}^{3}\) and 113.9 \(\pm\) 3.5 \(\upmu\)g/m\({}^{3}\), respectively). The concentration of monoterrenes outside the store varies from 11.63 \(\pm\) 1.7 \(\upmu\)g/m\({}^{3}\) in June to 34.3 \(\pm\) 2.9 \(\upmu\)g/m\({}^{3}\) in March, with an average of 21.3 \(\pm\) 7.5 \(\upmu\)g/m\({}^{3}\). The concentration of airborne particulate matter (PM) is presented in Figure 5. PM1, PM 2.5, and PM10 concentrations are higher outside than inside the shop. There is no clear trend regarding PM concentrations in different departments. Furthermore, the PM concentration in the sweets departments is higher in February and March, but in the rest of the year, it is not significantly different from other departments. The yearly average of outside PM1 concentration was 10.4 \(\pm\) 3.4 \(\upmu\)g/m\({}^{3}\), PM2.5 concentration was 19.0 \(\pm\) 4.7 \(\upmu\)g/m\({}^{3}\), and PM10 concentration was 25.4 \(\pm\) 5.2 \(\upmu\)g/m\({}^{3}\). The highest PM2.5 concentration value was found in October at a level of 24.0 \(\pm\) 0.8 \(\upmu\)g/m\({}^{3}\). In the department store, the lowest concentrations of airborne particulate matter were found in October and November. In order to estimate the health effects for inhabitants exposed to formaldehyde, the chronic daily intake (CDI) values for all departments were evaluated (Table 1).