Bacteriological Assessment of Indoor Air Quality in Keystone (Male) Hostel, University of Benin, Benin City

This study examined and identified the level of bacteria present in the hostel to evaluate the potential health hazards for the residents and establish guidelines for controlling indoor air quality. Six (6) rooms were sampled out of 25 rooms at the keystone hostel, each with a height of 10 feet, and an average dimension of 9 feet by 10 feet. The study was done in July and November, 2023. Passive air sampling of settle plate method was employed. The isolates were identified using standard cultural and biochemical identification method. The outcome revealed that the concentration of bacteria isolates rose as media exposure time increased. In July, the maximum bacteria concentration was observed in room 37 at 20min (21.5 x 102CFU/m3) and the minimum in room 49 at 20 min (0.02 x 102 CFU/m3. The concentration of bacteria in room 48 at 20 min was (0.1 x 102 CFU/m3), room 47 at 20 min (11.0 x 102 CFU/m3), room 38 at 20 min (16.5 x 102 CFU/m3), room 39 at 20 min (10.5 x 102 CFU/m3), While for the month of November, the highest bacteria concentration was seen in room 37 at 20min (26.5 x 102 CFU/m3) and the least at room 49 at 20 min (0.09 x 102 CFU/m3). The concentration of bacteria at other room 48 at 20 min (0.3 x 102 CFU/m3), room 47 at 20 min (13.5 x 102 CFU/m3), room 38 at 20 min (19.2 x 102 CFU/m3), room 39 at 20 min (15.1 x 102 CFU/m3). A total of seven (7) distinct bacteria species: Escherichia coli (60%), Staphylococcus aureus (100%), Streptococcus pyogenes (50%), Bacillus cerus (30%), Seratia marcescens (30%), Klebsiella spp (50%) and Proteus spp (50%) were isolated and identified in four rooms ( 37, 38, 39, and 47), with six occupants each, while room 48 and 49 had two occupants respectively; hence bacterial load were relatively non-significant. However, Staphylococcus aureus, Streptococcus pyogenes and Bacillus cerus were identified as the most pathogenic isolates seen in the rooms under study. The study highlights the potential impact of occupancy levels on microbial presence within indoor spaces. The results shows that students in rooms 37, 38, 39 and 47 have a high risk of health and disease implications due to poor ventilation and overcrowding, unlike the students in rooms 48 and 49 with low risk of infectious diseases. Therefore, the study recommends a periodic indoor air quality assessment in the students’ hostel, implementation of good health hygiene practices, maintaining environmental sanitation and managing the environmental factors that supports the multiplication of the bacteria especially in the dry season are crucial to preventing the spread of diseases in the hostel.