Mycological Quality of Indoor Air Environment in Undergraduate Female Student Hostels, University of Benin, Benin City, Nigeria

Abstract

This study was aimed at investigating the quantitative and the qualitative analysis of the indoor air mycoflora quality of two differently designed female undergraduate student hostels (Hall 1 and Hall 5) University of Benin, Ugbowo Campus, Benin City using the gravitational settled plate methods. The plates were exposed in nine rooms each of the hostel for about 30 minutes between the hour of 8 am and 12 noon at 1.5 meters above the ground level using the Potato dextrose agar and Sabouraud dextrose agar. This study was carried out between March, 2012 and August, 2012. The mean airborne fungal counts recorded in Hall 1 ranged between 0.41  0.13 x 10 3 cfu/m 3 and 3.88  2.24 x 10 3 cfu/m 3 while the mean airborne fungal counts in Hall 5 ranged between 0.29  0.07 x 10 3 cfu/m 3 and 4.41  2.99 x 10 3 cfu/m 3 . The highest airborne fungal counts were recorded in March, 2012 with the exception of Hall 1 which had its highest
count in June, 2012, while the lowest counts were recorded in August, 2012. The airborne fungal isolates obtained and characterized included fifteen fungal genera. They were Mucor spp., Aspergillus niger, Rhodotorula spp., Neurospora spp., Penicillium spp., Fusarium spp., Cladosporium spp., Geotrichum spp., Microsporium spp., Stachybotry spp., Botrydiplodia spp., Chaonophora spp., Curvularia spp., Botrytis spp. and Trichoderma spp. The percentage frequency of occurrence and distribution of the airborne fungal isolates in Hall 1 revealed Mucor spp., (12.75%), Aspergillus niger (11.44%), Cladosporium spp. (10.86 %) and Geotrichum spp. (10.80%) while Hall 5
had Mucor spp., (11.88%), Cladosporium spp. (11.31%) , Aspergillus niger (11.25%) and Geotrichum sp. (7.91 %) as the most frequently recorded airborne fungal isolates. The mean measurement obtained for temperature, relative humidity and number of occupants per room sampled revealed a mean temperature range of 28 o C to 29 o C with a mean range of 77% to 90% relative humidity recorded throughout the research period. An average number of 7 persons per room were observed in the two halls studied. Statistical analysis of the mean airborne fungal counts revealed that there was no significant difference (P > 0.05) for the airborne fungal counts obtained from the Hall 1 and Hall 5 between March, 2012 and August, 2012. The paired T-test analysis of the mean airborne fungal counts obtained in
Potato Dextrose Agar and Sabouraud Dextrose Agar showed no significant difference in Hall 5 while a significant difference was observed for Hall 1 (P > 0.05). This could be attributed to the newness of the new hostel (Hall 5) compared to the old one (Hall 1). The indoor air environment of the halls of residence examined revealed the prevalence of diverse groups of common indoor airborne mycoflora.