Indoor and outdoor microbial aerosols at the holy mosque: A case study

Abstract

The aim of this study was to evaluate bacterial and fungal aerosol concentrations at the holy mosque (Al-Masjid Al-Haram). Air samples were collected from different locations inside and outside the holy mosque, during the month of Ramadan-2011 (the fasting month), using a portable Air-port MD8 gelatin filter sampler. Trypticase soya agar and Capek's dox agar media were used to count bacteria and fungi, respectively. The mean concentrations of airborne bacteria and fungi ranged between 105–106 colony forming unit per cubic meter of air (CFU/m3) outside, and ∼102–105 CFU/m3 inside locations. The highest outside bacterial concentrations 106 CFU/m3 were found at the Al Umra, Al Fatah and eastern plazas, and the highest inside fungal concentrations ∼105 CFU/m3 were found at the courtyard, expansion of 1st floor, and roof. Significant differences (P < 0.05) were found between bacterial and fungal concentrations inside and outside sampling locations, higher concentrations shifted towards to outside locations. Significant differences were also found between the bacterial and fungal concentrations inside–unclosed and semi-closed (P < 0.05) with inside-closed locations. Gram-positive bacteria, Bacillus and Micrococcus, and fungi, Aspergillus niger were the dominant microbial aerosol genera. The obtained data is considered a step to make up the gap about airborne microbial contamination inside the holy mosque, and microbial air quality should be studied along over the year at the holy mosque in the future.