ASSESSING MICROBIAL CONTAMINANTS IN CLASSROOM AIR: A COMPARATIVE STUDY AT RIVERS STATE UNIVERSITY

Abstract

The presence of airborne bacteria in indoor environments poses significant health and environmental concerns, particularly in high-occupancy settings such as educational institutions. This study assessed the indoor air quality of selected classrooms at Rivers State University using the Koch sedimentation method to quantify microbial load and the Kirby-Bauer disc diffusion method to determine antibiotic susceptibility of bacterial isolates. Results revealed varying levels of aerobic bacterial load across classrooms. During peak classroom activity, the Faculty of Law recorded the highest load (1.18 × 10⁴ CFU/m³), followed by the Chemistry classroom (9.44 × 10³ CFU/m³), while the Psychology classroom had the lowest (1.28 × 10³ CFU/m³). After class activities, the Chemistry classroom retained the highest bacterial count (4.90 × 10³ CFU/m³). Identified bacterial genera included Bacillus, Staphylococcus, and Micrococcus. Antibiotic susceptibility testing showed Staphylococcus spp. were highly resistant to Ampiclox but sensitive to Gentamycin, Chloramphenicol, and Ciprofloxacin. Bacillus spp. were sensitive to multiple antibiotics, including Ampiclox and Erythromycin, while Micrococcus spp. showed no resistance to any tested antibiotics. The findings highlight the importance of indoor air monitoring and appropriate hygiene protocols in learning environments.