Microbiological assessment of indoor air quality of science laboratories in Olabisi Onabanjo University, Ago-Iwoye, Ogun State, Nigeria

Abstract

Laboratories are rooms equipped for performing scientific researches. Monitoring of bio-aerosols in laboratories will help to estimate the health hazards posed by airborne microorganisms and create standards for air quality control. This study was aimed at assessing the airborne bacteria present in the indoor environment of science laboratories in Olabisi Onabanjo University, Ago-Iwoye, Nigeria. Air samples were taken twice a day: in the morning and evening using the settle plate technique. Mean bacterial counts ranged from 236.6 CFU/m³ to 1530.0 CFU/m³. The highest mean bacterial count (1530.0 CFU/m³) was obtained at the Microbiology laboratory while the least count (236.6 CFU/m³) was obtained at the Physics laboratory. The bacterial count in the Microbiology laboratory was significantly higher than those obtained in the other labs ( p< 0.05) There was no significant difference in the bacterial counts obtained in the morning and the evening (p>0.05). The levels of pollution with bacterial aerosols in the laboratories ranged from intermediate to high. Four bacterial species were identified, with Bacillus species (33%) being the most frequently isolated followed by Staphylococcus aureus (27%), Micrococcus spp (23%) while the least isolated organism was Pseudomonas spp (17%). The level of bacterial contamination observed in these  laboratories calls for adequate sanitary measures to be put in place to control airborne bio-aerosols to safeguard the health of the users.