Microbiological Quality of Indoor Air in Some Selected Buildings at Modibbo Adama University of Technology, Yola

Abstract

The study aimed at investigating the quality of indoor air quality in some selected buildings at Modibbo Adama University of Technology Yola, Nigeria. Air samples were taken twice a week, morning and afternoon using settle plate method. In all the tested buildings a multiple growth of bacterial colonies and fungal spores were observed in the afternoons when compared to morning. The predominant bacteria isolated from the air samples were Staphylococcus aureus with frequency of 87.4%, Micrococcus spp. with frequency of 80.6%, Klebsiella pneumonia spp. with frequency of 47.0%, Actinomyces spp. with frequency 43.7% and Serratia mercenscens with frequency of 23.5%, while the isolated fungi included Cladosporium spp. with frequency of 66.2%, Aspergillus spp. with frequency of 57.6%, Penicillium spp. with frequency of 51.8% and Alternaria spp. with the frequency of 31.7%. The result of the determination of bacterial andfungal count showed that the highest count was found in the afternoon with461 CFU/m³ and 418 CFU/m³ while the lowest count in the morning with94 CFU/m³and 83 CFU/m³for both bacteria and fungi respectively. Among these microbes the presence of opportunistic pathogens that are involved in the establishment of sick building syndrome and saprophytic microflora which is generally associated to human skin and mucosa was detected. Possible causes of indoor air quality problem should be analyzed in order to retain healthy indoor environments. The  level of air contamination can be reduced by the application of some chemical and physical agents such as ultraviolet radiation and the use of air filters which has great potential value for reducing the microbial flora of the air.