Using the daily concentrations of individual compounds, the average weekly concentrations of the sum of an investigated VOC (PVOC) were calculated in order to determine the total level of
pollution in each environment (Fig. 1). Fig. 1 shows the hair salons in descending order according to PVOC concentrations; for each salon the standard deviation over the week was calculated. As the outdoor levels were comparable for all monitored sites, the averaged
value over all sites is shown in Fig. 1 as OUT to facilitate a comparison of this value with the indoor concentrations. It can be seen that the indoor levels were higher than the outdoor ones for each monitored site confirming the presence of indoor sources at these workplaces. Moreover, HS6 was the most polluted as it was characterized by a PVOC concentration equal to 3079 mg m3. On the other hand, HS4 and HS9 were the least polluted environments.