Introduction: Bioaerosols are agents that can cause infection, allergy or induce other toxic effects in the human body. If the person exposed to such particles is not capable of their destruction or elimination from the body, the established chemical and physiological disorders can result in disease or death. The aim of this study was to assess the concentrations of bioaerosols in several wards of a teaching hospital.

Methods: Given that gas air-conditioners (split and window types) were used for ventilation in the eye operating room, internal intensive care unit, and the respiratory isolation room, these wards were selected for passive sampling. Sterile plates containing culture medium were exposed for two hours to the wards’ indoor ambient air. After this time, they were transferred to a lab to undergo incubation, colony count, and identification of the microorganisms. The data were analyzed using SPSS software, version 18, and the significance level of less than 0.05 was used. 

Results: Based on our findings, the highest colony-forming bacterial unit was observed 22 cfu/plate/h in the eye operating room and, the highest colony-forming fungal unit was observed 4 cfu/plate/h in the internal intensive care unit. Based on the results of the differential tests, the most prevalent bacteria identified were Staphylococcus epidermidis (75%) in the air of eye operating room and Staphylococcus saprophyticus (52%) in the internal intensive care unit and isolation room. The most prevalent identified fungi in the air of selected wards were related to Alternaria alternata (43%), Aspergillus flavus (24%), Penicillium (36%) and Curvularia (21%) types. Based on Spearman's correlation test, no significant relationship was observed between the factor of temperature and the number of fungal and bacterial colonies (r = 0.201, p = 0.42; r = -0.197, p = 0.41). Moreover, a meaningful relationship was observed only between the number of individuals and the bacterial colonies present in the air (r = 0.749, p = 0.0001).

Conclusion: Comparing the number of diagnosed colonies by 25 cfu/plate/h value showed that the numbers of colonies in all samples were lower than the mentioned values. So, the air-conditioning systems’ performance in reducing the number of bioaerosols in the studied wards was satisfactory. However, since the remaining bacterial and fungal contamination can cause serious infections in patients, it is highly necessary that the cleaning intervals and replacement time points of such filters be programmed based on the number of individuals present in the wards and their active surgical hours.


Keywords: bioaerosol, hospital, air-conditioning, indoor air
» HTML Fulltext    » PDF Fulltext    » doi: 10.19082/2281
Kid's shoesNike

The  most recent editorial (June 2021)

Ethics of Publishing Case Reports: Do We Need Ethics Approval and Patient Consent?

An editorial by Dr. Mehrdad Jalalian

Read more.

The worldwide spread of COVID-19 as an emerging, rapidly evolving situation, and the dramatic need of urgent medicine or vaccine, has rapidly brought new hypotheses for pathophysiology and potential medicinal agents to the fore. It is crucial that the research community provide a way to publish this research in a timely manner.


To contribute to this important public health discussion, the Electronic Physician Journal is excited to announce a fast-track procedure to help researchers publish their articles on COVID-19 related subjects that fall under the broad definition of public health, internal medicine, and pharmacology. We are especially welcome to all hypotheses about the pathological basis of the COVID-19 infection and the possible characteristics of potential medicine and vaccine. Submit your manuscript here


Our previous editorial (June 2020)

Lessons from COVID-19 pandemic and the Morocco’s success story.

An editorial by Dr. Benksim Abdelhafid (Morocco)

Read more.


The 6th World Conference on Research Integrity (WCRI) is to be held on June 2-5, 2019 in Hong Kong.

The WCRI is the largest and most significant international conference on research integrity. Since the first conference in Lisbon in 2007, it has given researchers, teachers, funding agencies, government officials, journal editors, senior administrators, and research students opportunities to share experiences and to discuss and promote integrity in research. Read more:


TDR Clinical Research and Development Fellowships

Call for applications

Deadline for submission: 7 March 2019, 16:00 (GMT)

TDR provides fellowships for early- to mid-career researchers and clinical trial staff (e.g. clinicians, pharmacists, medical statisticians, data managers, other health researchers) in low- and middle-income countries (LMICs) to learn how to conduct clinical trials. Read more:

Meta-Analysis Workshops in New York, USA, and London, UK, in April and May 2019

Don't miss this exceptional opportunity to learn how to perform and report a Meta-analysis correctly. Two Meta-analysis workshops are organized in April and May 2019 by Dr. Michael Borenstein in New York, USA (April 08-10, 2019) and London, UK (May 27-29).

About the Instructor

Dr. Michael Borenstein, one of the authors of Introduction to Meta-Analysis, is widely recognized for his ability to make statistical concepts accessible to researchers as well as to statisticians. He has lectured widely on meta-analysis, including at the NIH, CDC, and FDA. Read more: