Abstract

With every breath, we inhale not only life sustaining oxygen but also dust, smoke, chemicals, microorganisms, and other particles and pollutants that float in air. The average individual inhales about 10 cubic meters of air each day.  Indoor air pollution and poor urban air quality are listed as two of the world’s worst toxic pollution problems in the 2008 Blacksmith Institute World’s Worst Polluted Places report. The present study investigated the microbiological indoor air quality within lecture halls, laboratory, library and offices within Dr. Ogbonnaya Onu Polytechnic, Aba; a tertiary institution in south east Nigeria, using standard microbiological methods. The results of the study showed that the air quality within these environment were contaminated having colony counts ranging from 2.1 ×10³, 1.6×10³, 1.1×10³ and 1.2×10³ (CFU/m³) for lecture halls, laboratory, library and offices respectively for total aerobic count. 1.0 ×10³ to 2.1×10³ for coliform count and 1.4 ×10³ to 4.8×10³ for total fungi count. The bacteria count of indoor air in some areas were above the WHO recommended limit (1000 CFU/m³ and 750 CFU/m³). Seven bacterial strains (Enterobacter, E. coli, Staphylococcus, Micrococcus, Pseudomonas, Serratia and Bacillus) and five fungi (Aspergillus, Penicillium, Rhizopus, and Cladosporium sp) were isolated from the air within these environments. Over population, students and staff activities and poor ventilation systems have being reported to influence the quality of air in a closed setting as it promotes the spread and transfer of infectious organisms and diseases. It is therefore of a public health concern that ventilation indoors should be adequate, numbers of staff in some offices and over populated lecture halls and laboratory should be reduced to avoid the spread air borne disease.