An Exploratory Study of Airborne Fungal Contamination and Its Association with Microclimate Conditions as Regards Sustainable Zoo Development

Air quality management in zoological gardens plays a crucial role in their sustainable development. However, air quality in these settings remains understudied. In addition, previous research has largely focused on airborne microbial contamination merely in animal enclosures. This exploratory study provides preliminary insights into airborne fungal contamination alongside microclimate conditions in the visitor and worker areas of animal premises in the Zagreb Zoo. The study was performed in the Monkey House, Tropical House, Rainy Africa, and Bird House, as well as outdoors in fall. Fungi were identified based on macroscopic and microscopic examinations. Total culturable fungal concentration in indoor air ranged between 50 and 4.25 × 103 CFU/m3, and in outdoor air between 1.00 × 102 and 1.50 × 103 CFU/m3. Molds of eight genera and yeasts were isolated from the air. Both indoors and outdoors, the predominant genera were Cladosporium and Penicillium, and also genus Aspergillus indoors. Cladosporium spp. and Penicillium spp. concentrations, as well as total fungal concentration in the air, were on average, highest in Rainy Africa and Bird House, while the highest average Aspergillus spp. concentration was found in the Tropical House. Levels of Cladosporium spp., Penicillium spp., and Aspergillus spp. concentrations were associated with microclimate conditions. Study results suggest that the airborne fungal contamination may depend on the animals housed in the premises, and the design and management of the premises. Although total fungal concentration determined may not necessarily pose a health risk for exposed people, the qualitative composition of fungi signifies the importance of implementing good practices in zoo premises, including optimal microclimate conditions and effective ventilation. The results obtained also indicate the need for air quality monitoring, which concurs with zoo sustainability goals.