Monitoring Important Indoor Air Quality Parameters in the Intensive Care Units of Selected Hospitals in Isfahan City, Iran, and Their Relationship With Environmental Parameters Publisher



Torabi Z ; Hajizadeh Y ; Mohammadi F ; Babaee SA
Source: Journal of Health System Research Published:2025

Abstract

Background: Improving air quality inside hospitals is very important for protecting the health of patients, staff, and visitors and controlling hospital infections. This study aimed to monitor indoor air quality parameters, including bacteria, particulate matter (PM10 and PM2.5), volatile organic compounds (VOCs), carbon monoxide (CO), and carbon dioxide (CO2) in the intensive care units (ICUs) of selected hospitals in Isfahan City, Iran, as well as investigating their relationship with environmental parameters. Methods: This descriptive cross-sectional study was conducted during two seasons, autumn 2022 and spring 2023. A total of 72 samples were collected and measured from 18 ICUs in 7 hospitals. The concentrations of VOCs, CO2, CO, PM10, and PM2.5 were measured with direct reading devices. An impinger containing phosphate buffer was used for sampling airborne bacteria, and tryptic soy agar (TSA) containing nystatin was used as culture media. Bacterial colonies were examined morphologically by Gram staining and observed under a microscope. Effective environmental factors were examined based on indoor air quality standards, and their relationship with air quality parameters was evaluated through statistical methods of analysis of variance (ANOVA) and Pearson correlation. Findings: The average of total bacteria, gram-positive bacteria, and gram-negative bacteria were 33.02, 31.52, and 1.52 CFU/m3, respectively. The average concentrations of PM10 and PM2.5 were 7.76 and 5.80 µg/m3, respectively, and the average concentrations of VOCs, CO2, and CO were determined to be 0.08, 141.05 ppm, and undetectable, respectively. Based on statistical analyses, no significant relationship was found between the concentrations of PM10, PM2.5, CO2, and CO and the level of bacteria, but the level of other air quality parameters was significantly related to some environmental factors such as temperature, humidity, air conditioning, and bed occupancy. Conclusion: Although the values of some air quality parameters were higher in some hospitals, especially in the autumn, they were generally not higher than the World Health Organization (WHO)-recommended standard limits. The suitability of air quality, especially in terms of the chemical parameters, indicates the improvement of hospitals, the presence of a ventilation system, an appropriate cooling and heating system, continuous washing of tools and equipment, and the prevalence of positive air pressure in the wards. However, to further improve the air quality of ICUs, it is necessary to comply with the standard number of beds, establish positive air pressure, and limit visits by relatives. © 2025 Elsevier B.V., All rights reserved.