- D3.514 - Atmospheric fungal spore content in an Arid Climate: One-year Seasonal Patterns in Doha, Qatar

Identification of region-specific airborne fungal spores improves the clinical relevance of allergy diagnosis by aligning sensitisation testing with local aeroallergen exposure. Doha, Qatar, has a hot desert climate with prolonged summers, mild winters, low rainfall, and intermittent high humidity. Rapid population growth and allergy clinic visits increasing highlight the need for local aerobiological studies. This study aimed to characterise airborne spore fungal types and their seasonal patterns to support the development of a local fungal spore calendar.

Fungal spores were continuously sampled from February 2024 to February 2025 using a Lanzoni VPPS 2000 seven-day volumetric sampler (10 L/min) installed on the rooftop of Building 310 (4-floors), Hamad Medical City, HMC, Doha, Qatar. Samples were weekly collected, mounted in glycerine jelly and analysed performing four horizontal sweeps according to the Spanish Aerobiology Network (REA) methodology (Galan et al., 2007). Fungal spores were identified by light microscopy at a ×400 magnification, daily mean concentrations being expressed as number of spores/m³ of air. Seasonal comparisons assessed species dominance and total fungal spore abundance.

Eleven fungal spore types were identified. Cladosporium dominated across all seasons, accounting for approximately 55–60% of total spores in winter and spring; remaining the most prevalent genus all year-round. Aspergillus was consistently the second most abundant spore type, with higher relative contributions during summer and autumn. Alternaria showed moderate and stable presence, while Deschlera demonstrated seasonal variability with an autumn peak. Other types, including Curvularia, Basidiomycetes, Torula, Ulocladium, Pithomyces, Myxomycetes, and Puccinia, contributed in a lesser extent (Figure 1).

Spore fungal content varied markedly from one season to another, peaking in spring (24,681 spores/m³), followed by autumn (16,343 spores/m³) and winter (13,892 spores/m³), with the lowest levels observed in summer (7,606 spores/m³). Lower summer counts may reflect environmental limitations related to frequent dust storms and reduced visibility rather than true absence of fungal spores.

Conclusion

Fungal spore content in Doha shows clear seasonal variations, with peak concentrations observed in spring and Cladosporium remaining the dominant pollen type throughout the year. These findings support the development of a Qatar-specific fungal spore calendar to enhance diagnosis accuracy and guide allergen avoidance strategies in clinical practice.

Acknowledgement

This research is part of MRC approved project (IRGC-07-SI-20-735).