Sampling efficiency of different particle samplers and the microscopic analysis of air borne pollen

Airborne pollen and fungal spores are part of the atmospheric coarse partic le mode. The collection of this particle fraction is a specially demanding task in total particle sampling. In order to examine the equivalence in sam pling efficiency of coarse particles, the pollen concentration was measured with a low volume sampler (KFG A-221) and a high volume sampler (Digitel D HA-80), each eqipped with an inlet for total particle sampling TSP), and th e Burkard pollen trap which is used as a standard instrument in European po llen networks. The samples were microscopically analysed for the pollen num ber of different species. Additionally, image analysis was employed in comb ination with real color processing. The field intercomparison showed a cons iderable oversampling for the pollen trap in comparison to conventional TSP samplers. An overestimation of pollen concentration is also indicated for TSP samplers with a downward air-flow in the inlet. For sampling of coarse bioaerosol particles it is recommended to employ TSP samplers with an annul ar slit inlet. In order to avoid a sedimentation input, samples should be t aken from an upward air flow depositing particles on a downward looking fil ter.