Characteristics of Airborne Particles and Bacteria in Hospital Indoor and Outdoor Air

Fatemeh Atoof; Sahar  Gholipour; Zahra  Shamsizadeh; Mohsen  Amirimoghaddam; Nezam  Mirzaei; Ali  Nazari-Alam; Davarkhah  Rabbani; Mansour  Baziar; Gholamreza  Hoseindoost; Gholamreza  Mostafaii; Abbas  Bahrami

doi:10.18502/jehsd.v8i4.14438

Fatemeh Atoof Department of Biostatistics and Epidemiology, Faculty of Health, Kashan University of Medical Sciences, Kashan, Iran.
Sahar Gholipour Social Determinants of Health (SDH) Research Center, Department of Environmental Health Engineering, Kashan University of Medical Sciences, Kashan, Iran.
Zahra Shamsizadeh Department of Environmental Health Engineering, School of Health, Larestan University of Medical Sciences, Larestan, Iran.
Mohsen Amirimoghaddam Department of Biostatistics and Epidemiology, Faculty of Health, Kashan University of Medical Sciences, Kashan, Iran.
Nezam Mirzaei Department of Biostatistics and Epidemiology, Faculty of Health, Kashan University of Medical Sciences, Kashan, Iran.
Ali Nazari-Alam Department of Microbiology and Immunology, Faculty of Medicine, Kashan University of Medical Sciences, Kashan, Iran.
Davarkhah Rabbani Department of Biostatistics and Epidemiology, Faculty of Health, Kashan University of Medical Sciences, Kashan, Iran.
Mansour Baziar Ferdows school of Paramedical and Health, Birjand University of Medical Sciences, Birjand, Iran.
Gholamreza Hoseindoost Department of Biostatistics and Epidemiology, Faculty of Health, Kashan University of Medical Sciences, Kashan, Iran.
Gholamreza Mostafaii Department of Biostatistics and Epidemiology, Faculty of Health, Kashan University of Medical Sciences, Kashan, Iran.
Abbas Bahrami Department of Occupational Health Engineering, Faculty of Health, Kashan University of Medical Sciences, Kashan, Iran.

DOI: https://doi.org/10.18502/jehsd.v8i4.14438

Keywords: Aerosols, Bacteria, Particulate Matter, Hospitals.

Abstract

Introduction: Given that hospital air is one of the important environmental sources for transmission of microorganisms, the importance of airborne transmission in the epidemiology of hospital-acquired infections (HAIs) has gained attention in the past two decades. Therefore, the present study aims to determine the concentration of bacteria in association with airborne particulate matter (PM) in the outdoor and indoor air of two hospital wards.

Materials and methods: The GRIMM 1.109 dust monitor and the Andersen one-stage viable impactor were used for particle counting and bioaerosol sampling, respectively.

Results: The average levels of airborne bacteria sampled from outdoor air were 33 colony-forming units (CFU/m³), and in the air samples of medical and infectious disease wards, they were 76 and 85 CFU/m³, respectively. Staphylococcus spp. and Acinetobacter spp. were the most prevalent bacteria in the samples. Statistical analysis showed a significant association between PM_2.5, and PM₁₀ particle mass concentrations and airborne bacteria concentrations in indoor air samples (P-value < 0.05).

Conclusion: Some bacterial agents of HAIs existed in hospital air and may be problematic for immunocompromised patients. Higher levels of bacteria in indoor air compared to outdoor air may indicate that the bacteria were of indoor origin, such as the presence and activities of people. Moreover, the results showed that particle counting may be a useful tool for airborne bacteria monitoring.