Grasses Pollen Concentrations In The Atmosphere Of Portugal

657 Grasses Pollen Concentrations In The Atmosphere Of Portugal E. Caeiro1, C. Nunes2, R. Brandao3, L. Lopes3, A. Gaspar4, M. Almeida4; 1University of Evora, Portimao, PORTUGAL, 2Center of Allergy of Algarve, Portimao, PORTUGAL, 3University of Evora, Evora, PORTUGAL, 4CUF Descobertas, Lisboa, PORTUGAL. RATIONALE: To compare the main pollination season (MPS) of Poaceae pollen from different monitoring stations of the Portuguese Aerobiology Network (RPA): Oporto (north), Coimbra and Lisbon (center), Evora and Portim~ao (south); 2) to analyse the interannual and diurnal variations of Poaceae pollen concentrations in the atmosphere of each station. METHODS: Airborne pollen was collected with Hirst-type samplers, most of them on rooftops or meteorological platforms, 15-20 m above ground floor. In this study, daily and hourly sampling data of Poaceae pollen from five monitoring stations over the last seven years (2002-2008) were used. RESULTS: There are differences between years. Daily average concentrations above 25 pollen grains/m3 were recorded in Oporto during 23 6 5 days, 16 6 8 days in Coimbra, in Lisbon during 34 6 15 days, in Evora 54 6 9 days and in Portim~ao 39 6 12 days. Poaceae pollen was recorded in the atmosphere during 24 hours, with the lowest values recorded between 22h and 6h and the highest values observed in Evora between 7h and 21h, where more than 30 pollen grains /m3 were recorded. CONCLUSIONS: Between the stations there were differences, in terms of quantity and other features by the different environmental conditions. The risk of exposure to this pollen is higher in the southern inland areas and rural areas