2018 No https://onlinelibrary.wiley.com/doi/10.1111/ina.12802 Ruggieri, Silvia Europe Observational Elementary (K-5) Temperature Carbon Dioxide (CO2) Particulate Matter (PM) Nitrogen Dioxide (NO2) Dust Air pollution Der p 1 Endotoxins Heavy metals Indoor comfort parameters Fine particulate matter (PM 2.5) Temperature and RH were within, or close to, the comfort range, while CO2 frequently exceeded the threshold of 1000 ppm, indicating inadequate air exchange rate. In all the classrooms, median NO2 levels were above the WHO threshold value. Dermatophagoides
p. allergen concentration was below the sensitizing threshold, while high endotoxin
levels were detected in the classrooms, suggesting schools may produce significant
risks of endotoxin exposure. Concentration and solubility of PM2.5 elements were
used to identify the sources of indoor particles. Indoor concentration of most elements
was higher than outdoors. Resuspension was responsible for the indoor increase
in soil components. For elements from industrial emission (Cd, Co, Ni, Pb, Sb,
Tl, V), the indoor concentration depended on penetration from the outside. For these
elements, differences in rural vs industrial concentrations were found, suggesting industrial
sources may influence indoor air quality nearby schools.