Urban Air Quality in Doha: A Year-long Examination of Bioaerosols and Public Health Implications

This study provides a thorough examination of ambient air bioaerosols in Qatar, specifically delving into the environmental aspects of bacteria, fungi, and viral diversity. The main objective is to elucidate the public health implications related to airborne superbugs and viruses in Qatar's unique arid climate, focusing on the urban areas of Doha. Bioaerosol samples were meticulously collected from eight distinct urban sites in Qatar throughout the year, covering diverse climatic conditions. Employing advanced methodologies, such as classical microbiology and next-generation sequencing, the samples underwent analysis to identify a wide range of pathogens, including bacteria, fungi, and viruses. The results obtained during the spatial-seasonal characterization of bacterial and fungal concentration in ambient air throughout the year reveal that bacterial and fungal diversity was higher in the summer (hot-dry) and winter seasons, respectively. The highest average concentration of total ambient bacteria and fungi was observed to be 130 CFU/m³ during the summer (dry-hot) and 40 CFU/m³ during the winter season, respectively. Notably, high bacterial concentration occurred in 80% of locations during the summer (dry-hot) season, while for fungi, it was 70% of locations during winter seasons. Fungal concentration was reported to be low during the summer (humid-hot) season. Culturable bacterial and fungal species were identified through detailed biochemical and microscopic analysis. Health-significant microorganisms identified include bacteria (Pseudomonas, Pasteurella, Pantoea, Proteus, Myroides, Chryseobacterium, Yersinia, Ochrobactrum, Sphingomonas, Vibrio) and fungi (Alternaria, Aspergillus, Fusarium, Rhizopus, Penicillium). The study detected the strongest antibiotic resistance during the summer (humid-hot) season, with all samples exhibiting resistance to Metronidazole, a common treatment for bacterial vaginosis and other inflammatory diseases. The investigation also yielded significant findings in two additional crucial areas: (i) Antibiotic Resistance Genes (ARG): Identification of critical and high-priority antibiotic-resistant strains, such as Acinetobacter baumannii and Staphylococcus aureus, indicating a significant public health concern for urban air quality. Temporal and spatial variations in ARG profiles further emphasized the complexity of the issue. (ii) Viral Diversity: A comprehensive array of viruses, including zoonotic and plant viruses, were detected. The presence of human pathogens like Escherichia coli and Orthohepevirus A (Hepatitis E virus) highlighted the potential for airborne disease transmission. This study underscores the intricate interplay between human, animal, and environmental health in urban ecosystems, aligning with previous research findings. The results emphasize the critical need for integrated surveillance to comprehensively understand bioaerosol composition and associated public health risks, especially in the context of Qatar's distinctive climatic conditions, where dust storms can significantly influence bioaerosol dynamics. The study advocates for heightened awareness and proactive public health measures to mitigate the risks associated with airborne pathogens and antibiotic resistance, aligning with recommendations from various health experts.