The influence of car traffic on airborne fungal diversity in Tianjin, China

Little is known about the effect of car traffic on airborne fungal communities. We investigated the environmental factors affecting the diversity and concentration of airborne fungi at high-traffic density junctions, in Tianjin, China. A total of 244 fungal strains belonging to 78 species and 45 genera of Ascomycota (78.69%) and Basidiomycota (21.31%) were isolated and identified using morphological and molecular analysis. Aspergillus was the species-richest genus, with 9 recorded species, followed by Alternaria and Cladosporium, both with 8 species. Coprinellus radians was the most abundant fungal species, with 31 isolated strains, followed by Alternaria alternata (26 strains), Cladosporium cladosporioides (21), Alternaria compacta (13), and Cladosporium tenuissimum (11). We found a higher diversity and concentration of airborne fungi in the analysed urban air environments when the road traffic was at its highest intensity. Higher level of car traffic resulted in higher concentrations of fungal particles in the air for various taxa, including Alternaria, Aspergillus, and Cladosporium, which are known to cause respiratory allergies and infections. This result suggests that reducing vehicular traffic could be an effective measure to control airborne fungal exposure and microbial pollution.