# Air Quality Assessment of a School in an Industrialized Area of Southern Italy
## 4 Conclusions  
During the winter of 2019, simultaneous indoor and outdoor VOCs monitoring, carried out through Radiello passive samplers and Photo Ionization Detectors (PIDs), was performed in a secondary school of Galatina (South Italy). The results highlighted that indoor TVOC concentrations were systematically larger than those outdoors, with a mean value of the I/O ratio equal to 1.41. TVOC profiles showed a decrease with the increase of wind speeds, or during Sundays. It is plausible to assume that the higher TVOC concentrations registered throughout the daytime school hours were due to student occupancy and poorly ventilated classrooms in the cold investigated period. Figure 7: Toluene/Benzene ratio in the monitored school areas. B1, indicates the male bathroom site; B2, the female bathroom site; 4B, classroom 4B; 4E, classroom 4E; and O4E, the external balcony of classroom 4E. Considering the VOC speciation performed by the Radiello cartridge sampling, it is possible to highlight that the average indoor concentration of toluene and xylene monitored were less than the values found in European schools as reported in the literature, while the average indoor concentration of benzene was larger. Moreover, benzene was always present in the highest concentrations in all indoor areas investigated, and the highest value was found on the balcony facing classroom 4E. Taking into account that the I/O ratio for benzene was less than 1, an outdoor source can be assumed for this pollutant. In particular, cigarette smoke is responsible for the high concentrations of benzene found, because the balcony of classroom 4E overlooks the main atrium of the school where students gather during break periods. The results suggest some recommendations to protect the students' health. The first measure is to encourage increasing ventilation in classrooms during school activities, and after cleaning. The second recommendation is to actively involve students in discussions regarding the use of acrylic paints, permanent markers, perfumes and deodorants, with a suggestion to limit the use of these products indoors all together. Another important recommendation would be to limit smoking activities in bathrooms, and also possibly in outdoor spaces. The following are available online at [[https://www.mdpi.com/article/10.3390/app11198870/s1](https://www.mdpi.com/article/10.3390/app11198870/s1)]([https://www.mdpi.com/article/10.3390/app11198870/s1](https://www.mdpi.com/article/10.3390/app11198870/s1)), Figure S1: Planimetry of the secondary school. 4B and 4E classrooms are highlighted, Figure S2: The time series of the daily average temperature and relative humidity (RH) data from 29 January to 10 March 2019, Figure S3: The time series of the daily average wind speed (SW) data from 29 January to 10 March 2019, Figure S4: The time series of the daily average rain and air pressure data from 29 January to 10 March 2019, Figure S5: Comparison between outdoor TVOC concentrations measured on the classroom balcony and NO\({}_{2}\) measured at the air quality monitoring station (AQI) during the selected sampling week, Figure S6: Benzene, Toluene, Ethylbenzene and Xylene indoor (classroom 4E) mean concentration values and relative reference ones. Conceptualization, P.I. and C.M. ; methodology, P.I., C.M. and P.F. ; software, A.D.; validation, P.I., C.M. and P.F. ; formal analysis, P.F., V.C., A.B., J.P., A.D.G., G.d.G. and A.D.; investigation, A.D.; resources, P.I. and C.M. ; data curation, A.D., V.C. and A.B. ; writing--original draft preparation, C.M. and A.D.; writing--review and editing, P.I. and P.F. ; visualization, J.P., A.D.G. and G.d.G. ; supervision, P.I., C.M. and P.F. All authors have read and agreed to the published version of the manuscript. This research received no external funding and was performed in the frame of a collaboration activity with the secondary school 'Liceo Scientifico e Linguistico--A- Vallone' of Galatina.