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Particulate matter (PM2.5) as a potential SARS-CoV-2 carrier
Norefrina Shafinaz Md Nor1, Chee Wai Yip1, Nazlina Ibrahim2
1Department of Biological Sciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia UKM, 43600, Bangi, Selangor, Malaysia.
Abstract:
The rapid spread of the SARS-CoV-2 in the COVID-19 pandemic had raised questions on the route of transmission of this disease. Initial understanding was that transmission originated from respiratory droplets from an infected host to a susceptible host. However, indirect contact transmission of viable virus by fomites and through aerosols has also been suggested. Herein, we report the involvement of fine indoor air particulates with a diameter of ≤ 2.5 µm (PM2.5) as the virus's transport agent. PM2.5 was collected over four weeks during 48-h measurement intervals in four separate hospital wards containing different infected clusters in a teaching hospital in Kuala Lumpur, Malaysia. Our results indicated the highest SARS-CoV-2 RNA on PM2.5 in the ward with number of occupants. We suggest a link between the virus-laden PM2.5 and the ward's design. Patients' symptoms and numbers influence the number of airborne SARS-CoV-2 RNA with PM2.5 in an enclosed environment.
Insights
Fine indoor air particulates, known as PM2.5, can transport the SARS-CoV-2 virus. Higher virus levels were found in more crowded hospital wards, suggesting a link to room design and patient factors.
Area of Science:
- Environmental Science
- Infectious Disease Epidemiology
- Aerosol Science
Background:
- The COVID-19 pandemic highlighted the need to understand SARS-CoV-2 transmission routes.
- While respiratory droplets were initially considered the primary mode, indirect transmission via fomites and aerosols became a concern.
- The role of specific airborne particles in virus transport required further investigation.
Purpose of the Study:
- To investigate the potential of fine indoor air particulates (PM2.5) as a transport medium for SARS-CoV-2.
- To determine the correlation between SARS-CoV-2 RNA on PM2.5 and hospital ward characteristics.
- To explore the influence of patient factors on airborne virus concentration.
Main Methods:
- Collection of PM2.5 samples over four weeks in four hospital wards with varying COVID-19 patient clusters.
- Utilized 48-hour measurement intervals for comprehensive air particulate analysis.
- Quantified SARS-CoV-2 RNA presence on collected PM2.5 samples.
Main Results:
- SARS-CoV-2 RNA was detected on indoor air PM2.5 samples.
- The highest concentrations of virus-laden PM2.5 were observed in wards with a greater number of occupants.
- A correlation was suggested between virus-laden PM2.5 and hospital ward design.
Conclusions:
- Fine indoor air particulates (PM2.5) can act as a transport agent for SARS-CoV-2.
- Hospital ward occupancy and design appear to influence airborne SARS-CoV-2 RNA levels on PM2.5.
- Patient symptoms and numbers are significant factors affecting airborne virus concentration in enclosed spaces.
