Megacities as hot spots of air pollution in the East Mediterranean

This paper provides a comprehensive overview of the actual knowledge on the atmospheric pollution sources, transport, transformation and levels in the East Mediterranean. It focuses both on the background atmosphere and on the similarities and differences between the urban areas that exhibited important urbanization the past years: the two megacities Istanbul, Cairo and the Athens extended area. Ground-based observations are combined with satellite data and atmospheric modeling. The overall evaluation pointed out that long and regional range transport of natural and anthropogenic pollution sources have about similar importance with local sources for the background air pollution levels in the area.

Research highlights► East Mediterranean is receptor and chemical cooker of transported air pollution. ► Megacities pollution sources are added to high regional background pollutant levels. ► Interactions between anthropogenic and natural emissions enhance air pollution. ► High regional O3 affected by different VOC/NOx levels and VOC speciation. ► Coating by pollutants increases dust solubility and deposition of nutrients.