P-11 Microbial Analysis of Indoor Air Quality and the Effectiveness of a Disinfection at a University Library
Author(s):
B Ally-Charles, E Tyrell, K Hohenkirk, A Hutson & O Van- Lewin
Type Of Study:
- Experimental or Intervention Study
Year of Presentation:
2024
Objective: To determine the microbial load of the air in the main library at the University of Guyana and to evaluate the effectiveness of a disinfection intervention on the microbial load of the air.
Methods: This was an experimental based study involving three phases of analyzing the microbial quality of the air, a disinfection experiment and a disinfection intervention. Phase 1 was done prior to rehabilitation of the library, phase 2 was done during the rehabilitation and phase 3 was carried out after the rehabilitation and a disinfection intervention. Samples were collected using the settle plate method and incubated according to standard laboratory procedures. Colony forming units (CFUs) were enumerated and the microbial load was determined via the Omeliansky equation. Several disinfectants were tested against two bacteria and the most effective ones were selected to design a specific disinfection protocol for use by the library cleaners.
Results: The bacterial load for phase 1 (13,114 CFU/m3) and phase 2 (7,636 CFU/m3) was higher than that of phase 3 (4,648 CFU/m3). The bacterial load between the three levels ranged between 2,739- 6,640 CFU/m3 for phase 1, 1,992- 3,486 CFU/m3 for phase 2 and 1,411- 1,743 CFU/m3 for phase 3. Although a limited number of settle plates were used to determine the fungal load, a high fungal load (4,067 CFU/m3) was noted before the disinfection intervention but no growth after.
Conclusion: We concluded that a high microbial load was found in our study prior to the disinfection intervention which was considerably diminished after the intervention. We recommend that the cleaning regimen we developed, be implemented as part of the library’s cleaning protocol.