Figure 4.
Figure 4A. Background Concentration Levels for PM 2.5
Figure 4B. Background Concentration Levels for EC
Figure 4C. Background Concentration Levels for OC
Figure 4D. Background Concentration Levels for EC/TC
Figure 4A. Background Concentration Levels for PM 2.5
Figure 4B. Background Concentration Levels for EC
Figure 4C. Background Concentration Levels for OC
Figure 4D. Background Concentration Levels for EC/TC