From: Divergent effects of urban particulate air pollution on allergic airway responses in experimental asthma: a comparison of field exposure studies
Particle size (μm)
Detroit (%)
Grand Rapids (%)
2. < 5
8.3
3.0
1.0 < 2.5
19.1
21.2
0.6 < 1.0
58.4
69.4
0.18 < 0.6
10.9
5.6
< 0.18
1.6
0.4