Table 1—

Indoor particulate matter with a 50% cut-off aerodynamic diameter of 10 μm (PM10), CO2 and ventilation rate in the classrooms

Centre, country (schools n, classrooms n)Mean (95% CI)sdMedianRange
PM10 μg·m−3
 Siena, Italy (4, 8)148 (88–208)7214169–247
 Udine, Italy (4, 8)158 (118–198)4815492–260
 Oslo, Norway (3, 6)54 (9–99)434317–131
 Uppsala, Sweden (4, 9)33 (23–43)133214–53
 Århus, Denmark (2, 7)169 (124–214)48160112–233
 Reims, France (4, 7)112 (90–135)2410686–151
 Total (21, 45)112 (91–133)6910614–260
CO2 ppm
 Siena, Italy (4, 8)1954 (1750–2157)24319701550–2359
 Udine, Italy (4, 8)1818 (1115–2520)8401563897–3475
 Oslo, Norway (3, 6)1158 (357–1959)763686634–2248
 Uppsala, Sweden (4, 9)681 (579–783)133657525–934
 Århus, Denmark (2, 7)1568 (965–2171)6521434561–2601
 Reims, France (4, 8)1660 (1407–1913)30316111199–2194
 Total (21, 46)1467 (1265–1670)6831490525–3475
Personal outdoor air supply rate L·s−1·person−1
 Siena, Italy (4, 8)2.61 (1.83–3.39)0.942.231.62–4.50
 Udine, Italy (4, 8)3.71 (1.42–6.00)2.752.871.52–9.38
 Oslo, Norway (3, 6)12.10 (3.93–20.27)7.7916.522.01–18.32
 Uppsala, Sweden (4, 9)16.88 (10.17–23.58)8.7214.586.31–34.97
 Århus, Denmark (2, 7)6.09 (2.02–14.20)8.773.141.79–25.91
 Reims, France (4, 8)3.16 (2.04–4.28)1.342.722.18–6.31
 Total (21, 46)7.46 (5.10–9.81)7.943.141.52–34.97