Exploring the Association between Hospital Air’s Physicochemical Parameters and its Microbial Profile in Some Egyptian Hospitals

Abstract

Background: Indoor air quality (IAQ) in hospitals may pose a risk of infection to patients. The objective of this study was to investigate the relationship between airborne microbial growth and various physicochemical characteristics of IAQ in hospital settings. Methods: A cross-sectional study was conducted in three hospitals in Egypt, between June 2022 and May 2023. The concentrations of total volatile organic compounds (TVOCs), carbon dioxide (CO2), temperature, relative humidity (RH), and particulate matter (PM), were measured in 168 indoor air samples. The selected locations were the operating room (OR), admissions department (AD), and intensive care unit (ICU). Passive air sampling was performed to culture airborne fungi and bacteria. Results: IAQ physicochemical values generally aligned with the WHO standards, with the exceptions of CO2 levels, which were between 700-800 ppm, and PM2.5, which was 15μg/m³. ADs had significantly higher temperatures, PM2.5, and PM10 levels compared to ORs (p<0.001), while ORs had higher RH% than AD (51.25±5.73 versus 47.60±8.48). The total fungal count was strongly negatively correlated with CO2 levels (r = -0.232, p = 0.003), but was strongly positively correlated with PM10 (r = 0.228, p = 0.003), particularly with mold counts (r = 0.330, p < 0.001). There was a strong positive correlation (r=0.477, p=0.014) between counts of airborne total fungi and relative humidity, while yeast counts and temperature had a substantial negative relationship (r=-0.483, p=0.019). Conclusions: There was a significant inverse relationship between airborne bacterial load and PM10 (r=-0.326, p=0.004) and total volatile organic compounds (r=-0.623, p<0.001).