The accession of Poland to the European Union involved the need or regional air quality assessment and brought radical change in requirements towards the sottware tools used for assessment purposes. According to Polish law, a zone is an agglomeration o rover 250 000 inhabitants, or a poviat (second level or local government administration in Poland), or a group of poviats, and assessment should consider both global and regional inllow or pollutants as well as the impact of local emission sources and significant sources in a voivodeship. These requirements have imposed a model range of over 250 km. Following an analysis or different models operating all over the world, the CALPUFF model together with the CALMET meteorological processor was chosen to be implemented in air quality assessment systems in Polish zones. This paper presents the results or model calculations performed within the air quality assessment in Mazowieckie voivodeship as well as compares them with the measurements obtained at automatic air monitoring stations.

At present. when high particulate matter (PM) concentrations in ambient air cause thousands o Ipremature deaths in Europe and global climate change is becoming the most critical issue in environmental protection, the state-of-the-science air quality and climate models constitute an essential research as well as decision support tools. Recently the great progress has been achieved in this research area. The present paper presents the goals and tools lor Air Quality (AQ) Modeling, and gives overview of' current challenges. including the meteurological. chemistry and climate modeling. The main emphasis is given to the regulatory and the Eulerian grid models. the latter arc currently operating as so called off-line or on-line modeling systems. The issues conncctccl with model implementation and validation is presented as well. finally, the conclusions arc drawn and rccornmcndations lor further development and integration ofAQ and climate modeling in Poland arc presented.