The pathogenic burden potential of airborne particles in emanating from the respiratory area of COVID-19 patients (a case study)

The pathogenic potential of airborne particles carrying the SARS-CoV-2 viral genome was examined by considering the size distribution of airborne particles at given distances from the respiratory zone of an infected patient after coughing or sneezing with a focus on time, temperature, and relative humidity. The results show an association between the size distribution of airborne particles, particularly PM₁ and PM_2.5, and the presence of viral genome in different stations affected by the distance from the respiratory zone and the passage of time. The correlation with time was strong with all the dependent factors except PM₁. Also, the effect of time intervals on the median concentration of airborne PM in the range of PM₇ and PM₁₀ was significant. Accordingly, in the first 20 min after coughing, the COVID-19 patient was more likely to be exposed to PM-carrying RNA genomes of SARS-CoV-2. The other finding was that the two distances of 0.25 m to the patient's left of the respiratory zone and 1.0 m above the breathing zone showed positive results for the presence of SARS-CoV-2 in all studied time intervals. The patterns of results suggested that there was a high potential for distribution of the virus in an infected patient based on position and airflow and that the severity of infection and viral load may influence the presence of viral load in droplets when coughing. Based on the results, one can conclude that ventilation plays a key role in mitigating the risk of airborne virus transmission in indoor environments, and it has been shown that reductions in particulate concentrations occur when portable air purifiers are placed near the breathing zone. The use of personal protective equipment for the patient and healthcare personnel to minimize the distribution of virus particles in the air is recommended.