Abstract:
Abstract
Background: Microbes in the indoor air environment pose serious health problems for millions of
children and adults. Microbial Indoor air quality problems in schools may be even more serious than in
other categories of buildings, due to a high number of students per classroom, insufficient outside air
supply, poor construction and maintenance of school buildings.
Objective: This study was aimed to assess microbial quality of the indoor air environment in public
primary schools and associated factors in Gondar city, Northwest Ethiopia, 2018.
Methods: Institutional based cross-sectional study was conducted among 51 randomly selected
classrooms from March 29- April 26, 2018. To determine the microbial count settle plate technique
were used by exposing Petri dish of blood agar media for bacteria and Sabouraud Dextrose Agar for
fungi for an hour. Airveda and Observational checklist were used to measure and assess the associated
factors. The Kruskal Wallis H test was used to show a significant difference microbial load in
classrooms. Generalized linear models regression analysis was done. Beta coefficient with 95%
confidence interval was used to determine the degree and direction of the association between the
predictors and the outcome variable.
Result: the lowest and highest mean bacterial population density was recorded at school 3 (279.5
CFU/m3) and school 5 (16302 CFU/m3). While, the highest and lowest mean fungal population density
was recorded at school 2 (2164.5 CFU/m3) and school 6 (136.5 CFU/m3). Staphylococcus spp. and
Bacillus spp. among bacterial species, Whereas Aspergillus (AS) spp., Penicillium (PE) spp., Candida
(CA) spp., Trichophyton (TR) spp., Alternaria (AL) spp., and, Fusarium (FU) among fungal spp. were
identified. Age of buildings (?= -0.122, 95 CI -0.238 - -0.007), area of classroom (?= 0.639, 95 CI 0.285
- 0.993), temperature (?= -0.189, 95 CI -0.325 - -0.047), humidity (?= -0.023, 95 CI -0.043 - -0.002) and
PM10 (?= -0.01, 95 CI -0.015 - -0.005) were associated with fungal load.
Conclusion: High microbial load was found in public primary school classrooms in the Gondar city as
compared with different indoor air biological standards. The age of buildings, the area of classroom,
temperature, humidity, and concentration of particulate matter in the classroom were significantly
associated with the mean fungal load. Staphylococcus spp. and Bacillus spp. among bacterial species,
Aspergillus (AS) spp., Penicillium (PE) spp., Candida (CA) spp., Trichophyton (TR) spp., Alternaria (AL)
spp., and, Fusarium (FU) among fungal spp. were identified.
Keywords: Classrooms, Indoor Air, Microbial Load, Settling Plate
