A year-round aeromycological study in Zagreb area, Croatia

Abstract

A 1-year aeromycological study was conducted in the area of Zagreb, the capital of Croatia, in order to establish seasonal variations in the composition and concentration of aeromycota. Sampling was carried out at 3 locations: the city centre, the Pharmaceutical botanical garden and the mountain of Medvednica, at regular intervals using the Mas 100 Eco Air-sampler with Sabouraud-dextrose agar. Airborne fungi peaked during spring and summer (110-284 cfu/m3), while lower levels were detected in autumn and winter at each of the 3 sampling sites (6-128 cfu/m3). Significantly lower concentrations were found in Medvednica region (p < 0.01) during most sampling periods. Yeasts were present in higher concentrations in autumn and winter (11-46 cfu/m3) than during spring and summer (9-11 cfu/m3) in the city centre and botanical garden. In the Medvednica region, yeasts were found at significantly lower concentrations than at other locations only during the autumn and winter (1-16 cfu/m3). The dominant fungi contributing to these differences were species of Cladosporium, Penicillium and Alternaria. These genera comprised between 30.4-79.5% of the samples. Other stable components of aeromycota were Fusarium, Aspergillus and sterile mycelia (11.1-44.0%). Total counts of airborne fungi as well as individual counts of Cladosporium and Alternaria showed significant positive correlations with temperature and solar radiation (p < 0.05). Alternaria also showed a significant correlation with wind speeds while Cladosporium was negatively correlated with atmospheric pressure (p < 0.05). Yeasts showed a significant positive correlation with relative humidity, yet were negatively correlated with temperature and solar radiation in the city centre and the botanical garden. In contrast, a significant positive correlation in the case of yeasts was observed in the Medvednica region with respect to temperature and solar radiation (p < 0.05).