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To evaluate the chemical fingerprint of hydrocarbons in airborne organic matter in the arid environment of Alexandria City, Egypt, the compositions of aliphatic and aromatic compounds were determined in suspended particulate material collected from a street undergoing heavy traffic in central Alexandria and in bulk deposition samples collected from a site representing an area increasingly influenced by human and industrial activities. Qualitative and quantitative characterizations of individual compounds were based on gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) analyses. More than 100 organic compounds are quantified in each sample, including n-alkanes, isoprenoids, polycyclic aromatic hydrocarbons (PAHs), sulfur-bearing heterocyclics, steranes/diasteranes, terpanes and aromatic steroids. The use of hydrocarbon profiles and ratios for identifying sources and processes is discussed. The molecular distribution of alkanes revealed that the main source of these compounds is from petroleum contamination with trace input of vascular plant wax. The PAH profiles, especially the relative abundance of alkyl-PAHs and sulfur-containing heterocyclics, showed that PAHs are chiefly derived from traffic sources. The results further indicated that diesel vehicles are more important PAH sources than gasoline vehicles. In addition, the source fingerprint of fossil fuel biomarkers such as steranes, terpanes and aromatic steroids agreed well with the fingerprint of unburned lubricating oil, which are probably contributed to vehicle exhaust emissions. [ABSTRACT FROM AUTHOR]

Assessment of spatial variations in the concentrations of potentially toxic metal Pb, Zn, Cu, Cr and Fe was carried out along three roads in Sfax region to identify possible changes in their levels. Concentrations were determined using atomic absorption spectrometer. The study found that for the samples collected along Gremda road the mean concentrations of Pb, Zn, Cr, Cu and Fe were from 2.5 to 110.3; 21.3 to 255.8; 0.8 to 13.7; 0.9 to 11.8 and 9190.8 to 17,267.7 µg/g, respectively. For the samples collected along Manzel Chaker road, obtained concentrations of Pb, Zn, Cr, Cu and Fe ranged between 1.6 and 36.2; 9.8 and 79.2; 2.1 and 7.1; 1.3 and 15.9; 3065.6 and 4084.4 µg g1− for Pb, Zn, Cu, Cr and Fe, respectively. For the sample of Tunis, they ranged between 6.8 and 60.2; 1.6 and 119.6; 1.2 and 6.7; 0.9 and 3.4 and 13,691.7 and 18,091.7 µg g1− for Pb, Zn, Cu, Cr and Fe, respectively. The use of different pollution indexes: geoaccumulation index (Igeo), contamination factor (CF), pollution load index (PLI) and enrichment factor (EF) showed the anthropogenic sources of Pb, Zn, Cu and Cr and the natural sources of Fe. The study indicated that the soils on the Gremda road are highly contaminated with Zn and Pb and no contamination with Cu and Cr. The other two roads showed lower contamination with Pb and Zn and no contamination with Cu and Cr. This difference is related to the variation in exposure to road emissions, the road activity and to the effect of climatic factors. [ABSTRACT FROM AUTHOR]

Little data are available on the levels of polycyclic aromatic hydrocarbons (PAHs) in the sediments of the Mediterranean Sea Coast of Egypt in general and the Alexandria coastal zone in particular. It was therefore deemed necessary to set up a monitoring programme to determine the current concentrations of PAHs in bottom sediments, and to identify any area where high concentrations of these potential hazardous contaminants were present in the Western Harbour of Alexandria. The composition, distribution and the source of PAHs in surficial sediments of the harbour were investigated. To document the spatial PAH input, surficial sediment samples from 23 locations throughout the harbour were analysed. as]Results and Discussion The total PAH load determined in the surficial sediment samples ranged from 8 to 131150 ng g1 dry wt, generally with most of the samples having total concentrations of PAHs greater than 5000 ng g1 dry weight. The highest concentration of total PAHs was recorded in sediments of the inner harbour. Ratio values of specific compounds such as phenanthrene to anthracene, fluoranthrene to pyrene, methyl-phen-anthrene to phenanthrene, methyl-dibenzothiophenes to dibenzothiophenes, alkylated to non-alkylated and high molecular weight to low molecular weight PAH, were calculated to evaluate the possible source of PAH contamination in the harbour sediments. Two main sources of PAH in the study area have been found: pyrolytic and petrogenic. Interferences of rather petrogenic and pyrolytic PAH contaminations were noticed for most samples. The dominant sources of PAH appear to be the combustion processes through run-off, industrial and sewage discharges, and atmospheric input. The concentrations of PAHs were generally above levels expected to cause adverse biological effects. Information from this study and any other relevant studies should be useful in designing future strategies for environmental protection and management of the harbour. [ABSTRACT FROM AUTHOR]