A Simplistic Method for Measurement of Bioaerosol in Indoor Air

Indoor air quality is a paramount concern due to its significant impact on human health, especially in the context of prolonged exposure. Bioaerosols, comprising tiny airborne particles carrying living microorganisms, contribute substantially to indoor air pollution. The COVID-19 pandemic has underscored the importance of monitoring indoor bioaerosols for infection control, allergy management, and overall air quality improvement. This study presents a simplified method for measuring bioaerosols in contaminated indoor air. The approach involves filtering indoor air through a sterilized 0.45 μ filter paper with a flow rate of 28–32 liters per minute (LPM) for a 5-min sampling duration. The filter is positioned on a stool 1 m above ground level, ensuring a minimum distance of 1 m from physical impediments. Tryptic soya agar in Petri dishes serves as the growth medium for bacterial species. Incubating the filter papers at 35 ± 2 °C for up to 72 h enables the observation of colony-forming units (CFU). The bioaerosol concentration is then expressed as CFUs/m3 based on the total volume of airflow. A compact monitoring kit developed for this purpose was used to assess bioaerosol concentrations in various classrooms and laboratories at the Indian Institute of Engineering Science and Technology (IIEST), Shibpur.