At the request of the contracting parties of the convention for the protection of the Mediterranean Sea against pollution, the WMO led GESAMP working group on the Interchange of Pollutants between the atmosphere and the oceans was invited to describe air pollutants transport process towards and into the Mediterranean Sea, and to review the scientific literature and assess the pathways and fluxes of important contaminants into the Mediterranean region. The first part of this report provides a review of the knowledge of the physical, chemical and biological processes which control the air-sea exchange of contaminants, along with a brief description of existing programmes in the Pacific Ocean, the North Atlantic, the Baltic sea, the North Sea and the Mediterranean Sea. The second part of this report discusses existing works relevant to the Mediterranean area. A limited data base exists for contamination of marine concern, with most information on air concentrations of heavy metals (particularly Cd and Pb), PCB's and n-alkanes, and very little information on concentrations in precipitation.