Enumeration and identification of dust fungal elements from the weather inversion phenomenon in Isfahan, Iran

Fungi are the major pathogens or allergens for which the air is the natural medium of their dispersal. Since the air pollution is associated with a wide range of adverse health outcomes, then identification of the type and population of fungi in these conditions will help the management of hygienic and control of fungal disease.

A total of 103 dust samples were collected from glass surfaces of different places by sedimentation method. Pollution standard indexes were provided by Environmental Protection Agency in Isfahan. All dust samples were mixed and homogenized in distilled water containing antibacterial agents. Serial cultures were done in 5 times experiments on two standard culture media. Isolated fungal colonies were identified by their standard morphologic and physiologic criteria. The analysis was performed by Mann-Whitney test calculating by SPSS version 20 (SPSS Inc., Chicago, IL, USA).

The real mean of total culture-able fungi in 1 g of sedimentation dust were account about 44800 colonies of different fungi. More than half of the viable fungi (62.8%) could grow out of 1 g of dust on Mycosel agar were the genera of Aspergillus, Penicillium and Cladosporium with 28.8%, 23.4% and 10.6% respectively. The dominant genus could grow on Sabouraud dextrose agar with chloramphenicol medium were the genera of Aspergillus, Cladosporium and Penicillium with 23.7%, 21.1% and 14.5% respectively.

Our data show the amount and variety of viable colony-forming fungi, which we are faced with in Isfahan during the air pollution condition. The real abundance of fungal particles and non-cultivable fungi in dust are still poorly understood and remain for further study in the future.