COMPARISON BETWEEN OUTDOOR AND INDOOR AIRBORNE ALLERGENIC ACTIVITY

Background: Allergenic pollens are usually detected in outdoor air by using volumetric spore traps, which allow measurement of atmospheric c oncentration as pollen grains per m(3) of air. The results of the poll en count are useful primarily for outdoor environments while most peop le spend most of the day indoors. Objective: The purpose of our study was to compare outdoor pollen levels with allergenic activity measured both outdoors and indoors. Methods: We used a Lanzoni spore trap to m easure airborne Urticaceae pollen and filters collecting particles sim ultaneously indoors and outdoors and assayed each filter for Parietari a judaica allergenic activity. Samples were collected at the Allergolo gical Service of the ''A. Cardarelli'' Hospital in Naples with the bal cony open on some days and closed on others. Allergenic activity (ng/m (3)) was measured using the immunocapture RAST. Results: With the balc ony open there was no great difference between outdoor and indoor alle rgenic activity, but with the balcony closed there was a reduction of indoor allergenic activity of about one-third in comparison with outdo or allergenic activity. Statistical analysis (Pearson correlation test ) indicated a significant correlation between outdoor allergen levels and indoor allergen levels with the balcony open (r = .4415, P < .05), but not with the balcony closed (r = .3160, P > .05); a significant c orrelation between outdoor pollen count and indoor allergen levels wit h the balcony open (r = .4809, P < .05), but not with the balcony clos ed (r = .3858, P > .05); and a highly significant correlation (r = .52 25, P < .001) between outdoor pollen count and outdoor allergen levels . Conclusions: These data provide scientific evidence for the recommen dation to hay fever patients to remain indoors during seasons with hig h levels of outdoor pollens.