Variation of selected air quality indicators over the city of Beirut, Lebanon: Assessment of emission sources

It is well established that the Mediterranean region experiences high pollution episodes as a result of its closed location and hot-humid long summers. However, few long-term field measurements have been conducted along the Eastern Mediterranean coast in general and in Arab countries, in particular. Hence, a six-month field study of major indicators like CO, SO2, PM10 and O-3 were conducted in Beirut, Lebanon. Measurements on an upwind site showed that the monthly average concentrations of CO, SO2 and O-3 were lower than the USEPA air quality standards while the monthly average concentrations of PM10 were higher. Diurnal variations showed that vehicle-induced emissions contribute significantly to CO levels while winter heaters constitute the major source of SO2. High diurnal and nocturnal levels of PM10 and O-3 are the results of several local and long-range transport phenomena. (c) 2006 Elsevier Ltd. All rights reserved.