Bioaerosol assessment of indoor air in hospital wards from a tertiary care hospital

Introduction & Objective: Exposure to microorganisms suspended in the air of both occupational and residential indoor environments is associated with a wide range of adverse health effects with major public health impacts. The quality of indoor air is one of the most significant factors affecting the health and well being of people. So the present study was conducted to assess bacteriological and fungal concentration of the indoor air of a teaching tertiary care institute hospital. Materials and Methods: The present study was carried for a period of three months from June 2018 to August 2018. Air sampling was performed with passive air sampling (settle plate’s methods) according to the 1/1/1 scheme (a Petri dish with a diameter of 9 cm was placed for 1 hour, 1 meter above the floor, and about 1 meter away from the walls). Each ward Petri dishes was exposed for 60 min in the morning and afternoon. Bacteria and fungi was collected on nutrient Agar, Blood Agar and Sabouraud Dextrose Agar(SDA). To obtain the appropriate surface density for counting and to determine the load with respect to time of exposure, the sampling times were set at 60 min in the morning (at 10.00-11.00 AM) and afternoon (2:00-3.00 PM). Both quantitative and qualitative analyses was conducted. Observation: The results indicate that the bacterial CFU/m3 air has been recorded in the range of 65.52 CFU/ m3 to 1179 CFU/ m3 at 60 min exposure. The results indicate that the fungal CFU/m3 air has been recorded in the range no growth to 262 CFU/ m3 at 60 min exposure. Gram Positive Bacteria were isolated more than Gram Negative Bacteria with predominance of Staphylococcus auerus. Whereas, the fungal isolates includes dominance of Candida spp followed by Aspergillus spp. Conclusion: This study revealed that hospital buildings were being ventilated by the aid of natural ventilation system which may increase the possibility of entrance of pollutants from unhygienic external environment. Modern built environ