Assessment of Indoor Microbial Quality of Science Laboratories at Three Universities in Gaza City

Abstract

Background: Good indoor air quality is important for human health and comfort, because people spend a substantial fraction of time within buildings. Microbial pollution is a key element of indoor air pollution. Bacteria and fungi growing indoors when sufficient moisture is available usually cause indoor air pollution. Objectives: To determine the total viable bacterial count and fungi levels and to compare these levels among various science teaching laboratories in Gaza city universities and to determine the humidity and temperature for labs. In addition, faculty offices were also evaluated. Methodology: Across-sectional prospective study was conducted on 2013. Sixty-five air samples were collected from three universities using Air Sampler. Samples were examined for total viable bacterial count and for fungi. Auto Ranging Multimeter was used to record humidity and temperature. Air samples with counts of bacteria or fungi more than 500 CFU/m3were considered polluted according to the Hong Kong standards. Results: Among the 65 samples, from three universities (Islamic, Azhar, Aqsa), 48 sample (73.8%) had more than 500 colonies/100L. 9 samples (13.8%) were shown to have more than 500 fungal CFU/m3.The highest percentage of bacterial load in air samples at the three universities (more than 500 CFU/m3) was at Islamic university (80.8%) and the lowest was at Aqsa University (61.5%). The highest percentage of fungal load in air samples at the three universities also was at Islamic university (19.23%) and the lowest was at Aqsa University. Chemistry departments were found to be most polluted departments with bacteria; 85.7% of samples were higher than 500 CFU/m3and the lowest were at Physics departments (60%). Environmental and earth science departments were shown to be the most polluted departments with fungi (28.6%) while the lowest were the Biology departments (0%). At the three universities, the faculty offices were found to be polluted more than laboratories, 90% of offices are polluted. Conclusion: A high percentage of the tested laboratories and offices were shown to have high bacterial and fungal levels. Precautions and safety measures should be taken to reduce microbial pollution at universities laboratories, to separate between labs and rooms and to improve labs ventilation and disinfection. Routine monitoring is advisable.