- D3.513 - Atmospheric Pollen Content in Arid Climate: One-year Seasonal Trends in Doha, Qatar

Pollen abundance is a major driver of allergic rhinitis and asthma; however, its clinical impact strongly depends on local vegetation and climatic conditions. In arid regions such as Doha, Qatar, with prolonged hot summers, short mild winters, minimal rainfall, and episodic high humidity influencing pollen production and dispersal, pollen profiles differ markedly from those described in temperate settings. With ongoing urban expansion and a growing population, understanding local pollen abundance has become increasingly important for optimising allergy diagnosis and management. This study aimed to characterise pollen spectrum and seasonal behaviour in Doha to support improved interpretation of allergy diagnostics and management.

Airborne pollen grains 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 (four floors) at 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). Pollen grains were identified by light microscopy at a ×400 magnification, daily mean concentrations being expressed as number of pollen grains/m³ of air. Seasonal analyses were carried out in order to evaluate pollen types dominance and relative abundance.

Twenty-nine pollen types were identified. Amaranthaceae was the predominant pollen group, contributing approximately 50% of the annual pollen load and remaining dominant across all seasons. Poaceae, the second most abundant pollen type (9%), followed by Cyperaceae (8%). Plantago accounted for 3% of total pollen grains. Among tree pollen, Arecaceae was the most prevalent (5%), followed by Prosopis (3%) and Conocarpus (2%).

Total pollen grains varied markedly depending on the season, peaking in autumn (5577 grains/m³), followed by spring (4058 grains/m³), summer (2326 grains/m³), and winter (955 grains/m³), corresponding to the following percentages: autumn (43%), followed by spring (32%), summer (18%), and winter (7%).

As previously reported, pollen monitoring identified Amaranthaceae as the most abundant pollen type in Doha, with meaningful contributions from grass, weeds, and some tree pollen types. These data provide a robust foundation to improve diagnosis accuracy and guide personalised allergen avoidance and treatment strategies in clinical practice.

Acknowledgement

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