Microbial Indoor Air Quality in a Secondary School in Port Harcourt City, Rivers State, Nigeria

The microbial air quality of a Secondary School in Port Harcourt was investigated between 9- 9:30am and 2-2:30am employing plate exposure and count method for bacteria and fungi estimation. Results obtained from the study showed that bacteria counts from the school for morning session ranged from 4.8 x 10^3 cfu/m^3 (Library) to 4.07 x 10^4 cfu/m^3 (Staffroom) and for the afternoon 9.8 x 10^3 cfu/m^3 (Library) to 4.66 x 104 cfu/m^3 (SS1A Classroom). Fungal counts ranged from 5.68 x 10^3 cfu/m^3 (Library) to 2.07 x 10^4 cfu/m^3 (SS3B Classroom) for the morning sessions and 6.56 x 10^3 cfu/m^3 (Library) to 2.59 x 10^4 cfu/m^3 (SS3B Classroom) for the afternoon session. Seven bacterial species, Bacillus spp., Enterococcus spp., Escherichia coli, Micrococcus spp., Pseudomonas spp. Staphylococcus aureus and Serratia spp and six fungal species, Alternaria spp., Aspergillus niger, Candida spp., Mucor spp., Penicillium spp., and Rhizopus spp were isolated. The bioaerosol concentrations were higher than recommended limit regardless of the sampling sessions. The high microbial counts and identified bacterial and fungal species may pose a serious problem to learning.