Since the eleventh session of GESAMP, at the request of UNEP, the Working Group on the Interchange of Pollutants Between the Atmosphere and The Oceans (INTERPOLL) focused its terms of reference on the description of transport processes towards and into specific regions. Using the Mediterranean as a model of a semi-enclosed sea, the Group examined horizontal atmospheric transport, vertical atmospheric transport to the air/water interface, and the interchange at this boundary. The Working Group also reviewed the scientific literature pertinent to this problem. During its fourth and fifth sessions which took place in Monaco in 1982 and in Athens in 1983, the Working Group discussed the specific requirements of the MED POL programme and made relevant recommendations. The reports of these two sessions were analyzed during the present meeting and used, along with more recent data, to produce the present interim report on atmospheric transport of contaminants into the Mediterranean Region.