Filtration efficiency of medical and community face masks against particles carrying SARS-CoV-2

Sara  Dalvand; Rasul  Nasiri; Rasoul  Yarahmadi; Farah Bokharaei  Salim; Ali Asghar  Farshad; Somayeh Soleimani  Alyar

doi:10.18502/japh.v9i4.17649

Sara Dalvand Department of Occupational Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran
Rasul Nasiri Air Pollution Research Center, Iran University of Medical Sciences, Tehran, Iran
Rasoul Yarahmadi Air Pollution Research Center, Iran University of Medical Sciences, Tehran, Iran
Farah Bokharaei Salim Department of Medical Virology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
Ali Asghar Farshad Department of Occupational Health and Safety Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran
Somayeh Soleimani Alyar Department of Occupational Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran

DOI: https://doi.org/10.18502/japh.v9i4.17649

Keywords: Face masks; Filtration capacity; SARS- CoV-2; Bioaerosol; Airborne particulates

Abstract

Introduction: Airborne bioaerosols like SARS-CoV-2 can pose a significant threat to the respiratory system of humans. Airborne bioaerosols, such as SARS-CoV-2, pose significant respiratory risks. Wearing respiratory masks is a preventive measure to reduce exposure and control the transmission of airborne diseases. Hence, this study aims to assess the effectiveness of the masks in filtering airborne particulates, specifically those that carry SARS- CoV-2.

Materials and methods: The filtration efficiency of three types of face masks was investigated for particulate matters in a laboratory setup using a custom-designed system, including a human head mannequin and controlled aerosol injection. Air samples were also collected from the breathing zone of COVID-19 patients in hospital settings, both with and without masks. Data analysis used Python tools, including Seaborn and Matplotlib, to generate visual insights.

Results: The study findings revealed variations in particle penetration and filtration efficiency of the tested masks for particles and SARS-CoV-2 based on mask types. The particles smaller than 700 nm penetrated N95 masks by 4.61%, with efficiency reaching 99.2% as particle size increased. Particle filtration efficiency for other masks, including surgical masks, ranged from 31%-68%, and for cloth masks, it was between 28%-86%.

Conclusion: The effectiveness of respiratory masks in preventing the transmission of airborne particles and viruses, like SARS-CoV-2, into the human respiratory system and regular use of suitable respiratory masks can help control disease transmission, especially in high-risk environments such as hospitals. In summary, using respiratory masks is essential in reducing the spread of airborne viruses and improving public health.