الفهرس 
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Abstract
The focus of this study was to make detailed characterization and quantification of motor vehicle related air pollutants along an urban street in Damietta City, to quantify the emissions of gaseous and particulate pollutants from traffic and to reduce vehicle emissions. Both gaseous emissions and particulate matters were collected at 7 sites. In order to study the air quality and the abatement of traffic related pollution in Damietta City, Egypt, the measurements campaign were conducted for a yearlong period covered four seasons (Starting from February 2008 to January 2009). Samples were collected for each site monthly during the study period. Air samples were collected at two heights in an urban canyon; at street-level (A) and at 6±2 m high rooftop level (B), at seven sites located at different traffic intensity, for 24-hrs periods at least once per a week/Site, at an urban background location over Damietta City, Egypt. The seven sites were selected on the basis of their strategic positions with varied traffic density and commercial activities in the City. The maximum concentrations of sulfur dioxide and nitrogen dioxide recorded in many streets in Damietta City can be attributed to the use of diesel fuel which represents 4.49 % in motorcycles, 3.13 % in passenger cars, 2.20 % in vans, 0.08 % in buses and 0.02 % in taxi. On the other hand, gasoline fuel represents 0.05 % in passenger cars, 0.02 % in buses, 0.79 % in vans and 0.02 % in taxi. In addition, natural gas is used as fuel for motor vehicles since 2008 in Damietta City and represents 0.01 % in passenger cars and taxi. The maximum mean annual concentration of SPM was 1065.01 mg/m3 recorded at heavily trafficked roads, Al-Harby Street (site 1). It can be concluded that the high concentrations of SPM in Damietta City atmosphere are mainly due to human activities beside the natural dust, that is highly dependent on the weather conditions. The average smoke concentrations ranged from 50.83 to 297.92 µg/m3 with average of 179.81 ± 45.94 µg/m3 for street level (A). This value is higher than the Egyptian standard limit (150 µg/m3, 24 hrs) and higher than the WHO Ambient Air Quality Standard (125 µg/m3, 24 hrs). It can be concluded that Pb has shown a good correlation with most of the investigated heavy metals at streets. Whereas, Cd has shown a negative correlation with Zn at most of the investigated streets. This indicates that the source profile and it’s variation in atmospheric levels do not match with other exhaust emissions. Some negative correlations between trace elements were observed. The annual mean concentration ∑PAH (∑ of 16 compounds) was 619.79 ng/m³. This value highly exceeded the results found by other investigators. The major constituent of PAHs in Damietta city was Benzo(a)anthracene with a value of 208.57 ng/m³, while the annual average concentrations of acenaphthene, the minor constituent, was 1.03 ng/m³. These values are higher than those found in Italy, Europe and other locations worldwide.