Indoor air quality in naturally ventilated and mixed model ventilation in public university of Pakistan

Airborne microorganisms have potential to cause infections and respiratory diseases like asthma. It is necessary to reduce the human exposure to such pathogens. This study was based on the determination of indoor environmental quality and the quantification of microbial load in a university premises in Karachi, Pakistan. Seven different locations with high human occupancy during office hours were sample din winter and summer. Culturable microorganisms i.e. bacteria and fungi were collected on selective media by Spin Air V2 sampler. The average bacteria and fungi concentration sin winter were133 ± 26colony forming unit per cubic meter (CFU.m-3) and 199 ± 59 CFU.m-3 respectively. In summer counts were higher than winter with bacterial and fungal count of 205 ± 39 and 306 ± 102 CFU.m-3. There was strong correlation (r = 0.8, p = 0.032) between fungal count and humidity, and between bacterial and fungal count (r = 0.802, p = 0.030). The most common culturable airborne fungi in both seasons were Aspergillus, Penicillium, Cladosporium, Fusarium, Alternaria, Stachybotrys, Candida, and Rhodoturola. Resultsindicate that the indoor environment in university premises harbours high concentrations of microorganism and needs regular indoor air quality monitoring and establish local guidelines to prevent diseases.