AIR POLLUTION – MONITORING MODELLING AND HEALTH

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Air Pollution – Monitoring, Modelling and Health
Emission factors (EFs)
The EFs from the three different sources are shown in Table 4. The differences of emissions
factors from three sources can partly be explained by the different quality of fuel and the
maintenance of vehicles. The motorcycle’s engines are not regularly maintained in Vietnam
and more than 60% of the motorcycles in Hanoi and in HCMC exceeded the emissions
standard (Trinh, 2007).
We evaluated the EFs from the 3 different sources. The main EFs which were used in this
study are the EFs from HCMC (NOx, NMVOC and CO). However, there is no data available
for the EFs of SO 2 and CH 4 for HCMC. So we used the emission factor of SO 2 from China
because the characterizations of China’s vehicles are similar to HCMC. For the emission
factor of CH 4 , we unfortunately had to use the emission factor of CH 4 from Copert IV. The
EFs and their uncertainties which were used in this study are shown in Table 4.
Vehicle NOx a CO a SO 2
b NMVOC a CH 4
c
Motorcycle 0.05±0.02 21.8±8.67 0.03±0.015 2.34±1.17 0.115±0.121
Bus 19.7±5.2 11.1±5.3 1.86±1.08 89.9±33.01 0.077±0.051
Light 1.9±0.9 34.8±15.5 0.05±0.029 15.02±7.36 0.017±0.018
Heavy 19.7±5.2 11.1±5.3 1.86±1.08 89.9±33.01 0.062±0.041
Car 1.9±0.9 34.8±15.5 0.18±0.105 15.02±7.36 0.0031±0.0032
Source:
a: the EFs were calculated for HCMC (Belalcazar et al., 2009; Ho et al., 2008)
b: the EFs of China (DOSTE, 2001)
c: the EFs were calculated from Copert IV.
Table 4. EFs (in g.km-1.vehicle-1) and their uncertainty.
- Result of total emissions:
The total result of traffic emission is presented in Table 5 as follows:
Pollutants Total emissions [ton h-1] Total uncertainties (%)
NOx 3.44 19.56
CO 331.4 33.77
SO 2 0.733 27.09
NMVOC 46.24 27.55
CH4 2.04 49.66
Table 5. The average of emission and their total uncertainties of all parameters over HCMC.
Temporal and spatial distribution
Temporal distribution: the vehicle flows from existing traffic counts were analyzed to derive
the temporal distribution (Fig.5).