First results of <Emphasis Type="Italic">Platanus</Emphasis> pollen airborne content in the middle-west of the Iberian Peninsula

The aim of this paper was to make a first approximation of the possible variations in Platanus pollen airborne content in Salamanca and Valladolid, Spain. Both cities were monitored during the 2005–2008 period; a greater number of pollen grains were collected in Valladolid, especially in 2007. The temperature influenced airborne pollen concentrations significantly (negatively during the main pollen season and the post-peak periods, and positively during the pre-peak period), conversely to rainfall and relative humidity. The intra-diurnal pattern was very similar for both towns, reaching a higher hourly concentration percentage in the second half of the day. The average intra-diurnal index values were 0.19 for Salamanca and 0.17 for Valladolid.