An applied aerobiological study to test the efficacy of pollen filters inlimiting indoor pollen contamination.

A simultaneous indoor and outdoor aerobiological monitoring was conducted to test the efficacy of a special pollen filter in impeding the entrance of aerobiological particles into living spaces and other structures marked by specific health needs. The efficacy levels of these membranes were tested through aerobiological monitoring carried out outdoors and indoors, in a special simulator located in the nearness and realised as a small-scale building model for simulating real indoor environments. The pollen monitoring carried out during approximately four months indicated a reduction in pollen concentration registered inside the special building simulator in comparison with the outdoor concentrations. The pollen reductions were different on the base of the different plant taxa. In particular, the highest percentages of reduction were recorded for the pollen of Poaceae and Cupro/Taxaceae (about 80%), while the lowest were those related to Urticaceae pollen (about 50%). These results can well be justified in consideration of the pollen size even if the artificial membranes were able to partially restrain the entering pollens utilising a special tissue with a uniform and consistent mesh width of about 70 μm, which is larger than the largest pollen deposited on the indoor monitoring apparatus.