Air pollution is globally significant because pollutants not only affect their source region, but also through transport they can affect other regions. The purpose of this study is to show the stand point of Turkey for EU directives. Sampling days that exceed PM10 limit values of EU PM10 restrictions are chosen as episode days for this research (PM10 > 150 mu g/m(3)). Two test cases representative of summer and winter are investigated in terms of stability conditions and synoptic fields. Considering these fields, the dominant phenomenon in generating pollution is defined as either the local sources contribution or the transport processes.