Environmental and Occupational Respiratory Diseases – 1031. A study of outdoor aeroallergens in Riyadh, Saudi Arabia

Results The data analyzed so far revealed the presence of different pollen and fungal species at both sites. The ratio between the pollen and fungal spores was 1:5. The airborne pollen grains showed quantitative and qualitative differences between the two sites. At FD site, the major pollen grains included Phoenix dactylifera (31%), grass pollen (14%), Atriplex nummularia (12%), Amaranthus viridus (10%), Artemisia monosperma (7%), Plantago sp. (6%) and Populus sp. (4%). The minor species (<1%) were Casuarina sp., Chenopodium murale, Eschscholtzia sp., Eucalyptus sp., Lilium sp., Prosopis juliflora, Salix sp. and Salsola imbricata. At the LD site, the major species included Phoenix dactylifera (36%), grass pollen (15%), Salix sp (8%), Artemisia monosperma (6%), Atriplex nummularia (6%), Plantago sp. (3%), Populus sp. (3%), Amaranthus viridus (2%) and Ambrosia sp. (2%). The minor species included Daucus carota, Eucalyptus sp. and Salsola imbricata. The fungal spores recorded at both sites displayed only quantitative variations. The major components of these spores at FD site included Arthrinium (14%), Ulocladium (14%), Cladosporium (13%), Alternaria (10%), ascospore septate (10%), smut spores (9%), Basidiospore (7%), ascospore non septate (6%), Bipolaris (3%), Myxomycete (3%), Periconia (3%), Aspergillus/Penicillium (2%), Stemphyllium (2%) and Curvularia (1%). The minor components (<1%) were Drechslera, Melanospora, Peranospora, Pithomyces and Torula. The major fungal spores at LD site were Ulocladium (13%), Cladosporium (12%), Aspergillus/Penicillium (11%), smut spores (11%), Alternaria (9%), ascospore septate (9%), Basidiospore (9%), Arthrinium (8%), Stemphyllium (5%), ascospore non septate (4%), Periconia (3%) and Bipolaris (2%), while the minor spores included Curvularia, Drechslera, Melanospora, Myxomycete, Peranospora, Pithomyces and Torula.