Vehicle Emission Factors for Particulate and Gaseous Pollutants in an Urban Tunnel in Xi’an, China

<div>Diurnal variations in five pollutants at site 2 during the sampling period. (a) Diurnal variations in PM<sub>2.5</sub> (left axes) and NO<sub><i>X</i></sub> and VOCs (right axes) for 11 days. (b) Diurnal variations in CO (left axes) and HC (right axes) for 11 days.</div>

Journal of Chemistry

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Figure 3

Figure 3: Vehicle Emission Factors for Particulate and Gaseous Pollutants in an Urban Tunnel in Xi’an, China 