Airborne Fungi Associated With Dust, their Source Identification and Contribution in the Southwest of Iran

Dust events impose negative socio-economic, health, and environmental impacts in vulnerable areas and reflect physiochemical and biological characteristics of their sources. The purpose of this study was to assess the impacts and contribution of two dust sources on concentration and diversity of airborne fungi in one of the most frequent dusty area in the world. Air masses arriving at study area were assessed using ground wind rose and HYSPLIT model. To explore the relationship between fungi in dust sources and downwind area, the sampling was carried out from airborne dust in Arvand Free Zone as targets areas and soil of dried part of Hor-alazim and Shadegan wetlands as sources areas. The samples were analyzed in the lab to extract DNA, PCR and sequencing. The Raw DNA data were processed using Qiime virtual box to pick OTUs and taxonomy assignments. The most common fungi at the Genus level were in the order of Penicillium > Aspergillus > Alternaria > Fusarium > Paradendryphiella > Talaromyces. The similarity between air and soil fungal genera was investigated using richness and diversity indices estimation, phyloghenetic tree, PCA analysis. results show the ambient fungi community structures in Hor alazim, and Shadegan dust sources were more similar to those on dusty days than non-dusty days. To quantify the contributions of known dust sources to airborne fungi, Source tracker model was used. Results show that the main known airborne fungi sources were the Hor-alazim in dusty and non-dusty days. This study's results can help managers to identify and prioritize dust sources in terms of fungal species.

Fungi Diversity in PM₁ and PM_2.5 at the summit of Mt. Tai: Abundance, Size Distribution, and Seasonal Variation

Fungi are ubiquitous throughout the near-surface atmosphere, where they represent an important component of primary biological aerosol particles. This study combined the internal transcribed spacer region sequencing and quantitative real-time polymerase chain reaction (qPCR) to investigate the ambient fungi in fine (PM2.5) and submicron (PM1) particles at the summit of Mt. Tai located in the North China Plain, China. The fungal abundance was 9.4 × 104 and 1.3 × 105 copies m−3 in PM2.5 and PM1, respectively. Most of the fungal sequences was from Ascomycota and Basidiomycota which are known to discharge actively spores into the atmosphere. The fungal community showed a significant seasonal shift across different size fraction based on the metastats analysis and kruskal-wallis rank sum test. The abundance of Glomerella and Zasmidium increased and decreased as the particle size got bigger in autumn. Nevertheless, Penicillum, Bullera, and Phaeosphaeria increased in smaller particles in winter. This work may serve as an important reference for the fungal contribution to primary biological aerosol particles.