Microbiological Air Quality in Healthcare Environments: A Review of Selected Facilities
Source abstract
Abstract
Exposure to microorganisms can significantly impact well-being and, more importantly, human health. A frequently overlooked aspect of indoor air quality (IAQ) research is the risk posed by harmful biological agents transported through the air in the form of biological aerosols. Given that healthcare facilities create environments with an increased risk of infection transmission, monitoring IAQ and reducing microbiological contamination have become global public health challenges. This paper presents a literature review, focusing on the current state of knowledge regarding microbiological air quality in healthcare settings. The analysis confirms that Escherichia coli and Staphylococcus aureus are among the most prevalent airborne pathogens in healthcare facilities. The review also underlines the necessity for harmonized guidelines and integrated air quality management strategies to reduce microbial contamination effectively. Finally, the review compiles data on microorganism concentration levels and influencing factors. The present study highlights that implementing standardized monitoring and effective air filtration and disinfection methods is essential to improving microbiological air quality and enhancing patient safety. The sources analyzed in this review were collected from databases such as PubMed, ScienceDirect, ResearchGate, and Web of Science, considering only English-language publications. The studies cited were conducted in multiple countries across different regions, providing a comprehensive global perspective on the issue.
Source: crossref · Quality: baseline
Research context
OpenAlex topics: Climate Change and Health Impacts · Infection Control and Ventilation · Indoor Air Quality and Microbial Exposure
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
Department of Technologies and Installations for Waste Management, Faculty of Energy and Environmental Engineering, Silesian University of Technology, 18 Konarskiego St., 44-100 Gliwice, Poland
Department of Air Protection, Faculty of Energy and Environmental Engineering, Silesian University of Technology, 22B Konarskiego St., 44-100 Gliwice, Poland
Funding
Faculty of Energy and Environmental Engineering, Silesian University of Technology
References (90)
Show source-provided references
1. Abundance of Airborne Heterotrophic Protists in Ground Level Air of South Dakota10.1016/S0169-8095(98)00109-4 ↗
2. Microbiological Indoor Air Quality in an Office Building in Gliwice, Poland: Analysis of the Case Study10.1007/s11869-018-0579-z ↗
3. The Size Distribution of Primary Biological Aerosol Particles in the Multiphase Atmosphere10.1023/A:1007607614544 ↗
4. ECDC (2025, May 10). Healthcare-Associated Infections, Available online: https://www.ecdc.europa.eu/en/healthcare-associated-infections.
5. WHO (2025, May 10). Key Facts and Figures. High-Level Messaging on the HAI and AMR Burden. Available online: https://www.who.int/campaigns/world-hand-hygiene-day/key-facts-and-figures.
6. Impact of Ultraviolet Light Disinfection on Reducing Hospital-Associated Infections: A Systematic Review in Healthcare Environments10.1016/j.jhin.2025.01.014 ↗
7. Szabó, S., Feier, B., Capatina, D., Tertis, M., Cristea, C., and Popa, A. (2022). An Overview of Healthcare Associated Infections and Their Detection Methods Caused by Pathogen Bacteria in Romania and Europe. J. Clin. Med., 11.10.3390/jcm11113204 ↗
8. Role of Air Changes per Hour (ACH) in Possible Transmission of Airborne Infections10.1007/s12273-011-0053-4 ↗
9. Biological Contaminants in the Indoor Air Environment and Their Impacts on Human Health10.1007/s11869-021-00978-z ↗
10. Airborne Particle Sizes and Sources Found in Indoor Air10.1016/0960-1686(92)90403-8 ↗
11. Bioaerozole w Budynkach Biurowych
12. Assessment of Personal Deposited Dose and Particle Size Distribution of Bacterial Aerosol in Kindergarten Located in Southern Poland10.1016/j.envpol.2023.123208 ↗
13. Role of Bioaerosols in Indoor Air Quality and Respiratory Diseases
14. A Review of Indoor Microbial Growth across Building Materials and Sampling and Analysis Methods10.1016/j.buildenv.2014.05.030 ↗
15. Sources, Compositions, Spatio-Temporal Distributions, and Human Health Risks of Bioaerosols: A Review10.1016/j.atmosres.2024.107453 ↗
16. Understanding the Influence of the Bioaerosol Source on the Distribution of Airborne Bacteria in Hospital Indoor Air10.1016/j.envres.2022.114458 ↗
17. Double Trouble: The Interaction of PM2.5 and O3 on Respiratory Hospital Admissions10.1016/j.envpol.2023.122665 ↗
18. Ambient Air Pollution and Risk of Respiratory Infection among Adults: Evidence from the Multiethnic Study of Atherosclerosis (MESA)10.1136/bmjresp-2020-000866 ↗
19. Chawla, H., Anand, P., Garg, K., Bhagat, N., Varmani, S.G., Bansal, T., McBain, A.J., and Marwah, R.G. (2023). A Comprehensive Review of Microbial Contamination in the Indoor Environment: Sources, Sampling, Health Risks, and Mitigation Strategies. Front. Public Health, 11.10.3389/fpubh.2023.1285393 ↗
20. Effects of Human Activities on Concentrations of Culturable Bioaerosols in Indoor Air Environments10.1016/j.jaerosci.2016.11.008 ↗
21. Kauch, K., Halladin, M., Patoń, N., Rytczak, J., Szczęsny, M., Palmowska, A., and Brągoszewska, E. (2023). Ocena Efektywności Działania Urządzeń Oczyszczających Powietrze Wewnętrzne w Zakresie Usuwania Szkodliwych Czynników Biologicznych (SCB). Nowoczesne Rozwiązania w Ochronie Środowiska. Zagadnienia Wybrane, Wydawnictwo Naukowe TYGIEL.
22. Narażenie Na Aerozole Ziarniste, Włókniste i Biologiczne (Bakterie i Grzyby Mikroskopijne) Populacji Generalnej Górnośląskiego Okręgu Przemysłowego
23. Airborne Pathogenic Microorganisms and Air Cleaning Technology Development: A Review10.1016/j.jhazmat.2021.127429 ↗
24. (2025, February 19). Układ Oddechowy—Opis Układu i Jego Chorób. Available online: https://vitamarket.pl/g6-Uklad-oddechowy.html.
25. Indoor Air Quality Levels in a University Hospital in the Eastern Province of Saudi Arabia10.4103/2230-8229.128778 ↗
26. Microbiological Indoor and Outdoor Air Quality of Two Major Hospitals in Benin City, Nigeria
27. Sivagnanasundaram, P., Amarasekara, R.W.K., Madegedara, R.M.D., Ekanayake, A., and Magana-Arachchi, D.N. (2019). Assessment of Airborne Bacterial and Fungal Communities in Selected Areas of Teaching Hospital, Kandy, Sri Lanka. Biomed. Res. Int., 2019.10.1155/2019/7393926 ↗
28. Variability of Airborne Microflora in a Hospital Ward within a Period of One Year
29. Microbiological Assessment of Indoor Air Quality at Different Hospital Sites10.1016/j.resmic.2015.03.004 ↗
30. Assessment of the Levels of Airborne Bacteria, Gram-Negative Bacteria, and Fungi in Hospital Lobbies10.3390/ijerph10020541 ↗
31. Airborne Bioaerosols in Healthcare Facilities—Transmission Routes and Mitigation Strategies: A Review10.1016/j.jobe.2024.111015 ↗
32. Voidazan, S., Albu, S., Toth, R., Grigorescu, B., Rachita, A., and Moldovan, I. (2020). Healthcare Associated Infections—A New Pathology in Medical Practice?. Int. J. Environ. Res. Public. Health, 17.10.3390/ijerph17030760 ↗
33. The Role of the Hospital Environment in the Healthcare-Associated Infections: A General Review of the Literature
34. ECDC (2025, May 09). Most Frequently Isolated Microorganisms, Available online: https://www.ecdc.europa.eu/en/all-topics-z/healthcare-associated-infections-long-term-care-facilities/surveillance-and-disease-5.
35. Update on Bacterial Nosocomial Infections—PubMed
36. Health Care-Associated Infections—An Overview10.2147/IDR.S177247 ↗
37. Staphylococcus Cohnii: Not so Innocuous10.4103/2221-6189.219624 ↗
38. Nosocomial Infections and Their Control Strategies10.1016/j.apjtb.2015.05.001 ↗
39. Staphylococcus Cohnii Endocarditis in Native Valve10.1016/j.nmni.2020.100825 ↗
40. A Rare Case of Invasive Enterococcus Cecorum Infection and Related Diagnostic Difficulties10.1002/ccr3.9386 ↗
41. Aspergillus Spp. Osteoarticular Infections: An Updated Systematic Review on the Diagnosis, Treatment and Outcomes of 186 Confirmed Cases10.1093/mmy/myac052 ↗
42. ECDC (2025, May 11). Healthcare-Associated Infections in European Hospitals (PPS Survey) 2022–2023, Available online: https://www.ecdc.europa.eu/en/publications-data/healthcare-associated-infections-european-hospitals-pps-survey-2022-2023.
43. Quantification and Analysis of Airborne Bacterial Characteristics in a Nursing Care Institution10.3155/1047-3289.61.7.732 ↗
44. Ozone Exposure Leads to Changes in Airway Permeability, Microbiota and Metabolome: A Randomised, Double-Blind, Crossover Trial10.1183/13993003.00165-2020 ↗
45. Narodowy Instytut Zdrowia Publicznego PZH (2025, May 10). Zalecenia Dot. Działań Mających Na Celu Ograniczenie Ryzyka Związanego z Przenoszeniem Się Wirusa SARS-CoV-2 Za Pośrednictwem Systemów Wentylacyjno-Klimatyzacyjnych Wewnątrz Budynków Użyteczności Publicznej Oraz Wielkopowierzchniowych Obiektów Handlowych, Available online: https://www.gov.pl/web/psse-aleksandrow-kujawski/zalecenia-dot-dzialan-majacych-na-celu-ograniczenie-ryzyka-zwiazanego-z-przenoszeniem-sie-wirusa-sars-cov-2-za-posrednictwem-systemow-wentylacyjno-klimatyzacyjnych-wewnatrz-budynkow-uzytecznosci-publicznej-oraz-wielkopowierzchniowych-obiektow-handlowych.
46. Airborne Spread of Infectious Agents in the Indoor Environment10.1016/j.ajic.2016.06.003 ↗
47. Location-Allocation Modelling for Rational Health Planning: Applying a Two-Step Optimization Approach to Evaluate the Spatial Accessibility Improvement of Newly Added Tertiary Hospitals in a Metropolitan City of China10.1016/j.socscimed.2023.116296 ↗
48. Spatial Accessibility of Primary Health Care in China: A Case Study in Sichuan Province10.1016/j.socscimed.2018.05.023 ↗
49. ASHARE (2019). Health Care Facilities. ASHRAE Handbook—HVAC Applications, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.
50. Bonadonna, L., Briancesco, R., Coccia, A.M., Meloni, P., La Rosa, G., and Moscato, U. (2021). Microbial Air Quality in Healthcare Facilities. Int. J. Environ. Res. Public. Health, 18.10.3390/ijerph18126226 ↗
51. Methods for Air Cleaning and Protection of Building Occupants from Airborne Pathogens10.1016/j.buildenv.2008.09.001 ↗
52. EPA (2025, May 10). What Is a HEPA Filter?, Available online: https://www.epa.gov/indoor-air-quality-iaq/what-hepa-filter.
53. Atkinson, J., Chartier, Y., Lúcia Pessoa-Silva, C., Jensen, P., Li, Y., and Seto, H. (2009). Natural Ventilation for Infection Control in Health-Care Settings, World Health Organization.
54. The Characterization of Upper-Room Ultraviolet Germicidal Irradiation in Inactivating Airborne Microorganisms10.1289/ehp.0211095 ↗
55. Inactivation of Airborne Bacteria Using Different UV Sources: Performance Modeling, Energy Utilization, and Endotoxin Degradation10.1016/j.scitotenv.2018.11.266 ↗
56. Survival of Bioaerosols in HVAC System Photocatalytic Filters10.1016/j.apcatb.2013.07.036 ↗
57. Photocatalytic Oxidation Technology for Indoor Environment Air Purification: The State-of-the-Art10.1016/j.apcatb.2016.10.037 ↗
58. Plasma Air Filtration System for Intercepting and Inactivation of Pathogenic Microbial Aerosols10.1016/j.jece.2023.110728 ↗
59. Distribution of Exhaled Contaminants and Personal Exposure in a Room Using Three Different Air Distribution Strategies10.1111/j.1600-0668.2011.00736.x ↗
60. Indoor Air Quality: Current Status, Missing Links and Future Road Map for India
61. Chemical-Physical and Microbiological Measurements for Indoor Air Quality Assessment at the ca’ Granda Historical Archive, Milan (Italy)10.1007/s11270-008-9931-5 ↗
62. Heseltine, E., and Rosen, J. (2009). WHO Guidelines for Indoor Air Quality: Dampness and Mould, WHO.
63. Microbiological Analysis of Bioaerosols Collected from Hospital Emergency Departments and Ambulances10.26444/aaem/80711 ↗
64. Seasonal and Spatial Variations of Bioaerosols and Antibiotic Resistance Bacteria in Different Wards of the Hospital
65. Baudet, A., Baurès, E., Guegan, H., Blanchard, O., Guillaso, M., Le Cann, P., Gangneux, J.P., and Florentin, A. (2021). Indoor Air Quality in Healthcare and Care Facilities: Chemical Pollutants and Microbiological Contaminants. Atmosphere, 12.10.3390/atmos12101337 ↗
66. Božić, J., Ilić, P., and ilić, S. (2019). Indoor Air Quality in the Hospital: The Influence of Heating, Ventilating and Conditioning Systems. Braz. Arch. Biol. Technol., 62.10.1590/1678-4324-2019180295 ↗
67. Tselebonis, A., Nena, E., Panopoulou, M., Kontogiorgis, C., Bezirtzoglou, E., and Constantinidis, T. (2020). Air Contamination in Different Departments of a Tertiary Hospital: Assessment of Microbial Load and of Antimicrobial Susceptibility. Biomedicines, 8.10.3390/biomedicines8060163 ↗
68. Environmental Factors and Ventilation Affect Concentrations of Microorganisms in Hospital Wards of Southern Thailand10.1155/2020/7292198 ↗
69. Risk Factors for Particulate and Microbial Contamination of Air in Operating Theatres10.1016/j.jhin.2007.05.019 ↗
70. Characterization of Indoor Bioaerosols from a Hospital Ward in a Tropical Setting10.4314/ahs.v12i2.22 ↗
71. de S.; Alves, V.F.; Bara, M.T.F.; Torres, I.M.S. Potentially Pathogenic Bacteria Isolated from Neglected Air and Surfaces in Hospitals10.1590/s2175-97902020000418989 ↗
72. A Study of Air Microbe Levels in Different Areas of a Hospital10.1007/s00284-009-9398-7 ↗
73. Aspergillus Surveillance Project at a Large Tertiary-Care Hospital10.1016/j.jhin.2004.05.017 ↗
74. Bacteria Emitted in Ambient. Air during Bronchoscopy—A Risk to Health Care Workers?10.1016/j.ajic.2016.04.241 ↗
75. Indoor Air Quality-Induced Respiratory Symptoms of a Hospital Staff in Iran10.1007/s10661-018-7182-5 ↗
76. Assessment of Bacterial Pathogens and Their Antibiotic Resistance in the Air of Different Wards of Selected Teaching Hospitals in Tehran10.4103/ijoem.IJOEM_234_19 ↗
77. Evaluation of Bio-Aerosols Concentration in the Different Wards of Three Educational Hospitals in Iran10.4103/2277-9183.105346 ↗
78. Evaluation of Hospital Wards Indoor Air Quality: The Particles Concentration
79. Assessment of Fungal Contamination in a Portuguese Maternity Unit10.2495/EHR110121 ↗
80. ECDC (2025, March 03). Factsheet for the General Public—Antimicrobial Resistance, Available online: https://www.ecdc.europa.eu/en/antimicrobial-resistance/facts/factsheets/general-public.
81. Frye, J., Galgano, M., Pellegrini, F., Catalano, E., Capozzi, L., Del Sambro, L., Sposato, A., Stella Lucente, M., Iris Vasinioti, V., and Catella, C. (2025). Acquired Bacterial Resistance to Antibiotics and Resistance Genes: From Past to Future. Antibiotics, 14.10.3390/antibiotics14030222 ↗
82. Gajic, I., Tomic, N., Lukovic, B., Jovicevic, M., Kekic, D., Petrovic, M., Jankovic, M., Trudic, A., Culafic, D.M., and Milenkovic, M. (2025). A Comprehensive Overview of Antibacterial Agents for Combating Multidrug-Resistant Bacteria: The Current Landscape, Development, Future Opportunities, and Challenges. Antibiotics, 14.10.3390/antibiotics14030221 ↗
83. Microbial Regulation of Natural Antibiotic Resistance: Understanding the Protist-Bacteria Interactions for Evolution of Soil Resistome10.1016/j.scitotenv.2019.135882 ↗
84. Multidrug-Resistant Gram-Negative Bacterial Infections in a Teaching Hospital in Ghana10.1186/s13756-018-0324-2 ↗
85. Antimicrobial Resistance Patterns in Clinically Significant Isolates from Medical Wards of a Tertiary Care Hospital in North India10.1055/s-0040-1721161 ↗
86. Merk, H., Diaz Högberg, L., Plachouras, D., Suetens, C., and Monnet, D.L. (2022). Assessing the Health Burden of Infections with Antibiotic-Resistant Bacteria in the EU/EEA, 2016–2020.
87. Global Burden of Bacterial Antimicrobial Resistance 1990–2021: A Systematic Analysis with Forecasts to 205010.1016/S0140-6736(24)01867-1 ↗
88. Poletajew, S., Pawlik, K., Bonder-Nowicka, A., Pakuszewski, A., Nyk, Ł., and Kryst, P. (2021). Multi-Drug Resistant Bacteria as Aetiological Factors of Infections in a Tertiary Multidisciplinary Hospital in Poland. Antibiotics, 10.10.3390/antibiotics10101232 ↗
89. Antimicrobial Resistance Trends in Bloodstream Infections at a Large Teaching Hospital in China: A 20-Year Surveillance Study (1998–2017)10.1186/s13756-019-0545-z ↗
90. Evaluating the Relationship Between Hospital Antibiotic Use and Antibiotic Resistance in Common Nosocomial Pathogens10.1017/ice.2017.222 ↗