Total pollen counts do not influence active surface measurements

We investigated the temporal association of various aerosol parameters with pollen counts in the pollen season (April 2001) in Linz, Austria. We were especially interested in the relationship between active surface (or Fuchs’ surface) because we had shown previously (Atmos. Environ. 37 (2003) 1737–1744) that this parameter during the same observation period was a better predictor for acute respiratory symptoms in school children (like wheezing, shortness of breath, and cough) and reduced lung function on the same day than particle mass (PM10). While active surface is most sensitive for fine particles with a diameter of less than 100 nm it has no strict upper cut-off regarding particle size and so could eventually be influenced also by larger particles if their numbers were high. All particle mass parameters tested (TSP, PM10, PM1) were weakly (r approximately 0.2) though significantly correlated with pollen counts but neither was active surface nor total particle counts (CPC). The weak association of particle mass and pollen counts was due mainly to similar diurnal variations and a linear trend over time. Only the mass of the coarse fraction (TSP minus PM10) remained associated with pollen counts significantly after controlling for these general temporal patterns.