INTRODUCTION
Air is among the most basic requirements for survival it stands out as the most invaluable. This perhaps is why it fills the space around us as an invisible substance in the natural environment. Air contributes most importantly oxygen to humans and other live forms, microorganisms are not an exception to this besides they are abundant in the air as a result of wind kicking up dust, blowing up water or individuals coughing, sneezing, spitting and shouting. Microorganisms are harmful and their presence in air has been confirmed (Hayleeyesus and Manaye, 2014; Kunwar et al., 2019; Al-Taweil et al., 2020).
So many microbial infections often referred to under the term “communicable diseases” are transmitted through air because their causative agents abound there especially within closed spaces; hospitals, classrooms, libraries, account for high prevalence of microbes in air (51%, 33%, 16% respectively), drawing a major concern for indoor air quality. Research studies on indoor air quality have isolated and identified Escherichia coli (15%), Micrococcus abd Streptococcus sp (12.5%), Staphylococcus aureus (27.5%), Bacillus sp. (22.5%), Pseudomonas (10%), species from air within the closed spaces enlisted earlier and common diseases such as cough, common cold, sore throat and pharyngitis have resulted thereof (Fekadu and Getachewu, 2015; Enitan et al., 2017; Amengialue et al., 2017; Kunwar et al., 2019; Andualem et al., 2019; Al-Taweil et al., 2020; Agwaranze et al., 2020).