Exhaust component
|
Filtered air (n = 30)
|
Unfiltered DE (28)
|
Diesel exhaust filter A (n = 29)
|
Diesel exhaust filter B (n = 28)
|
---|
PM1 (μg/m3)
|
4.6 ± 1.7
|
350 ± 72
|
183 ± 18***
|
93 ± 16***
|
Particle number x 105/cm3
|
n/a
|
54 ± 10
|
30 ± 6*
|
15 ± 3**
|
NO (ppm)
|
0.00 ± 0.00
|
2.49 ± 1.01
|
2.21 ± 0.66
|
1.77 ± 0.55**
|
NO2 (ppm)
|
0.00 ± 0.00
|
0.68 ± 0.29
|
0.58 ± 0.20
|
0.10 ± 0.04***
|
Hydrocarbons (ppm)
|
0.00 ± 0.00
|
2.41 ± 0.81
|
1.85 ± 0.60*
|
1.02 ± 0.11***
|
- Data are given as mean ± SD. T-tests were performed to analyze differences in pollutant concentrations between unfiltered DE and DE exhaust after the use of the cabin filters. P values of < 0.05 were considered significant: *P < 0.05, **P < 0.01, ***P < 0.001.