Table 1

 Concentration of RSP2.5 particles (mg/m3)

Vehicle typeFully open windowHalf open windowClosed windowp Value§
Mean (SD) (n)*Mean (SD) (n)*Mean (SD) (n)*
*n, number of measurements; †fully open window versus half open (Mann—Whitney test, p<0.05); ‡fully open window versus closed (Mann–Whitney test, p<0.05); §Kruskal–Wallis test; ¶half open window versus closed (Mann–Whitney test, p<0.05); PCV, passenger cabin volume; SD, standard deviation.
Two-door pick-up utility vehicle4.57 (1.43)† ‡ (90)4.89 (2.06)¶ (76)12.77 (7.53) (99)<0.001
PCV = 1.4 m3
Three-door small city car1.33 (0.76)† ‡ (82)5.32 (3.00)¶ (86)13.15 (6.59) (45)<0.001
PCV = 2.5 m3
Five-door station wagon5.28 (1.80)† ‡ (72)12.15 (3.63) (80)12.37 (5.63) (68)<0.001
PCV = 3 m3
Baseline measurement0.013 mg/m3