Assessment of Airborne Microbial Contaminants Using Passive Sampling Technique

The primary aim of this study was to evaluate airborne microbial contaminants in a laboratory setting using a passive sampling technique. Results indicated higher counts of bacteria in the air of the laboratory at ceiling level (total bacteria = 5.36±0.06 log10 CFU/m3; total coliform = 3.69±0.37 log10 CFU/m3) compared to near the ground (total bacteria = 5.17±0.01 log10 CFU/m3; total coliform = 3.45±0.06 log10 CFU/m3). Conversely, filamentous fungi showed higher counts closer to the ground (4.19±0.27 log10 CFU/m3) than from the ceiling (3.82±0.40 log10 CFU/m3). The total bacterial count in the air from ceiling was significantly higher than above ground level (P <0.05). High counts of total bacteria, filamentous fungi, and coliform bacteria contributed to the presence of these microorganisms on working surfaces (total bacteria = 24.17±19.08 CFU/m2; total coliform = 1.69±1.03 CFU/m2; filamentous fungi = 7.07±3.59 CFU/m2), equipment (total bacteria = 29.22±25.22 CFU/m2; total coliform = 1.47±1.05 CFU/m2; filamentous fungi = 4.87±3.83 CFU/m2), door knobs (total bacteria = 15.83±11.50 CFU/m2; total coliform = 0.33±0.00 CFU/m2; filamentous fungi = 3.83±1.83 CFU/m2), and chairs (total bacteria = 32.78±35.91 CFU/m2; total coliform = 1.11±0.16 CFU/m2; filamentous fungi = 3.44±2.74 CFU/m2). The highest count of total bacteria was observed on the chair, while the working area had the highest counts of coliform bacteria and filamentous fungi. Data from this study showed that the microbial load of bacteria and filamentous fungi in the laboratory exceeded acceptable limits. The results from this study could be used as basis in the implementation of effective aseptic techniques and rigorous laboratory practices which are essential to prevent the spread of handled microorganisms and to minimize cross-contamination from environmental microorganisms.