Indoor air quality management suggests that any bat droppings present indoor or near the residence or office environment is of major health concern and a potential health hazard. This is due to the suspicion of the presence of fungal material and their growth in bat droppings. The molds that grow in moist, warm, highly organic bat droppings are known to increase asthma attacks in affected people. To find out the presence of fungi in bat droppings a study was conducted on the droppings of Mexican Free-tailed Bats (Tadarida brasiliensis) . The droppings were collected from "The world's biggest urban bat roosting colony" i.e. Congress Avenue Bridge of Austin, Texas.

 

Altogether 9 species belonging to 5 genera of fungi were recorded from the droppings of T. brasiliensis apart from yeast colonies and non-sporulating colonies.  The colonies belonging to yeasts dominated the droppings and contributed around 40.8% followed by Cladosporium sphaerospermum (25.56%), C. cladosporioides (23.33%) and C. chlorocephalum (8.8%) in the order of dominance. The direct microscopic observation yielded only 4 spore types apart from the hyphal fragments. The number of insect scales exceeded 216,500/gm on an average. It is concluded that the presence of yeast colonies in large numbers may emerge as a pathogen of the exposed human subject and immunocompromised individuals. The dry, airborne insect scales may also function as an irritant to the respiratory system of the exposed subjects.