Seasonal periodicities of fungal allergens in the atmosphere of Riyadh

ABSTRACT

Aerobiological studies to evaluate allergenic fungal spores in the atmosphere of Riyadh were conducted using Burkard volumetric 7-day recording spore trap and culture plate techniques from November 1986 through October 1987. Thirty-two generic and morphologic categories were recorded. The majority of these fungal spores belonged to dry-air spore of conidial fungi, originating from garbage, rubbish bins, stored fruits and vegetables, and the like. Cladosporium spp. Constituted 24.8% [mean value] of total air spora over the 12-month period, ranging monthly from 8.5% to 40%; smuts [Ustilago and other species] 13.4% [range, 1.6% to 25.6%]; Alternaria spp. 5.6%[range, 1.9% to 9.6%]; Ulocladium spp. 3.4% [range, 1.0% to 6.8%]; Chaetmium 1.8% [range, 0.7 to 4.2%]; Drechslera and Helminthosporium 1.8% [range, 0 to 5.4%]. Basidiospores constituted 3.1% [rage, 1.5% to 5.7%]. Peak hourly concentrations for all categories were recorded, Cladosporium having the highest concentration. Seasonal periodicities showed an increase in concentration in the warmer months and a decline in the winter