Saba Fouladvand - Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
Majid Nozari - Department of Environmental Health Engineering, School of Public Health, Bam University of Medical Sciences, Bam, Iran
Kazem Nadafi - Corresponding author: Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
Mahmood Alimohammadi - Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
Meraj Khalui - Department of Nutrition, Zahedan University of Medical Sciences, Zahedan, Iran
Mohammad Sadegh Hassanvand - Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
Mohammad Reza Pourmand - Department of Pathobiology, School of Public Health, and Biotechnology Research Center, Tehran University of Medical Sciences, Tehran, Iran

Background: Research on the relationship between bioaerosols and particulate matter (PM) concentrations is necessary, especially in hospitals where airborne bioaerosols can facilitate disease transmission. This study aimed to investigate the relationship between PM (PM۲.۵ and PM۱۰) and bioaerosols, as well as the factors influencing them (temperature and humidity), in the air of liver transplant operating rooms (LTOR) at Imam Khomeini Hospital in Tehran. Methods: Bioaerosol samples (۳۲ samples) were collected using the passive sampling method, employing open-door plates containing culture medium, during June and July of ۲۰۱۹. PM samples were obtained concurrently with bioaerosol samples using the GM۸۸۰۳ air quality detector, during four one-hour periods. Simple linear regression analysis was performed to determine the relationship between bioaerosol and PM concentrations. Results: It was revealed that the average concentrations of PM۲.۵ and PM۱۰ were ۱۷.۸ (SD = ۲.۲) and ۲۷.۰ (SD = ۲.۶) μg/m۳, respectively. Additionally, the average concentrations of bacterial and fungal bioaerosols were ۲۱۳۲ (SD = ۸۳۷) and ۵۵۰ (SD = ۱۸۹.۴) CFU/m۲.h, respectively. Linear regression analysis demonstrated a strong correlation between bacterial bioaerosols and PM concentrations, whereas the relationship with fungal bioaerosols was relatively weaker. Conclusion: The findings of this study indicate that the indoor air in LTOR exhibits a higher level of microbial contamination than the recommended guidelines for high-risk environments. To improve the air quality in LTOR, it is recommended to implement periodic microbial monitoring, ensure the proper functioning of ventilation systems, and pay attention to their maintenance and operation.

Air pollution, Indoor, Particulate matter (PM), Operating room (OR), Passive sampling