... traffic in Ho Chi Minh City Ho Minh Dzung*, Dinh Xuan Thang Institute for Environment and Resources, Vietnam National University, Ho Chi Minh City Received 24 December 2008; received in revised ... observed at this period of the day. From 2 pm to 6 pm, the wind direction is oblique to the street axis and the wind speed is higher than in the morning. At these hours of the day, tracer ... will depend on the ability of the model to reproduce the dispersion of the pollutants. Until now, in Vietnam in general and HCMC in particular, the study on determining the emission factors...