Speciation of Pb, Cu and Zn determined by sequential extraction for identification of air pollution sources in Syria

Speciation of three trace elements (Zn, Pb, Cu) in air particulates of two Syrian cities (Tartous and Darya) with different climate conditions and industrial emissions has been studied. Air filters were collected during 2000–2001 and extracted chemically using different selective fluids in an attempt to identify the different forms of trace elements. Approximately 60% of lead in air particulates of both cities was found to be associated with organic materials produced by incomplete burning of vehicles fuels and residential heating; the remaining 40% of lead was as lead oxides and mineral acids soluble compounds. Zinc was found in oxides (28–65%) samples collected in Tartous city, indicating that the Tartous cement factory and phosphate loading cargoes are the main source of emissions. In the Darya filters, zinc associated with organic materials (28–49%) was related to the presence of plastic molding industries and corroding car tires. In addition, copper was also found to be in the form of oxides (19–46%) in both cities in the summer periods, while 13–25% and 35% are associated with organic materials and silicates, respectively. Differences in chemical forms of the studied trace elements in air particulates were found to be related to differences in air pollution sources and differences in human behaviour throughout the year. Therefore, chemical fractionation of trace elements in air particulates using sequential leaching can be used for identification of air pollutions sources in urban and industrial areas.