Study of airborne bacterial load in indoor environments

The load of airborne microorganisms in indoors depends of factors such as human occupancy, ventilation status, cleanliness, maintenance of rooms etc. As many airborne bacteria are pathogenic, periodic sampling of air helps to provide insight into the quality of air and also ensure the health and safety of individuals being exposed. The objective of this work is to study the airborne bacterial load in indoor environments. The bio-aerosol samples were collected from different classrooms and labs with the help of an LA002 Air Sampler System, on to Nutrient Agar medium by exposing for a period of 5 minutes. The plates were incubated at 37 ºC for 24 hours and colonies developed were studied. The results revealed the prevalence of Gram negative rod shaped organisms. The microbial load was found to be more in non-AC classrooms than AC ones, as well as more in the samples taken during occupied state than in vacant.