Meteorological and agricultural effects on airborne Alternaria and Cladosporium spores and clinical aspects in Valladolid (Spain).

The aeropalynological monitoring was carried out from 1 February 2005-31 January 2007. The total number of spores collected during the main spore season (MSS) in 2005 was 4,500 for Alternaria and 93,744 in the case of Cladosporium, whereas in 2006 values were increased (8,385 for Alternaria and 150,144 for Cladosporium), reaching the maximum concentrations on 18 July and 17 June 2006 with 344 and 5,503 spores, respectively. The influence of the main meteorological parameters on spore concentrations was studied, resulting in a positive correlation with temperature. Rainfall, relative humidity and frequency of calms obtained negative correlations in the case of Alternaria, and positive for Cladosporium, the total daily hours of sunshine having an inverse influence on them. The intra-diurnal pattern was very similar for both genera, with a greater representation towards the central hours of the day and at night. Finally, some clinical aspects for the Alternaria spore type were analyzed, with a low percentage of sensitized patients though (9.5%). Only one patient showed positive skin test reaction to Cladosporium.