Effectiveness of different types of mask in aerosol dispersion in SARS-CoV-2 infection

• Published in: International journal of infectious diseases Vol. 109; pp. 310 - 314
• Main Authors: Tanisali, Gokhan, Sozak, Ahmet, Bulut, Abdul Samet, Sander, Tolga Ziya, Dogan, Ozlem, Dağ, Çağdaş, Gönen, Mehmet, Can, Fusun, DeMirci, Hasan, Ergonul, Onder
• Format: Journal Article
• Language: English
• Published: Canada Elsevier Ltd 01.08.2021; The Author(s). Published by Elsevier Ltd on behalf of International Society for Infectious Diseases; Elsevier
• Subjects: Aerosol dispersion; Aerosols; Cough; COVID-19; Humans; Mask types; Masks; SARS-CoV-2; Schlieren Imaging; COVID-19; Mask types; SARS-CoV-2; Schlieren Imaging; Aerosol dispersion
• ISSN: 1201-9712; 1878-3511; 1878-3511
• DOI: 10.1016/j.ijid.2021.06.029

•No difference was found in the spread of aerosols between single and double surgical masks.•Mask fit is crucial in preventing the spread of aerosols.•Cloth masks can be used, although standardization is necessary. To compare the effectiveness of different mask types in limiting the dispersal of coughed air. The Schlieren method with a single curved mirror was used in this study. Coughed air has a slightly higher temperature than ambient air, which generates a refractive index gradient. A curved mirror with a radius of curvature of 10 m and a diameter of 60 cm was used. The spread of the cough wavefront was investigated among five subjects wearing: (1) no mask; (2) a single surgical mask; (3) a double surgical mask; (4) a cloth mask; (5) a valveless N95 mask; and (6) a valved N95 mask. All mask types reduced the size of the contaminated region significantly. The percentage reduction in the cross-sectional area of the contaminated region for the same mask types on different subjects revealed by normalized data suggests that the fit of a mask plays an important role. No significant difference in the spread of coughed air was found between the use of a single surgical mask or a double surgical mask. Cloth masks may be effective, depending on the quality of the cloth. Valved N95 masks exclusively protect the user. The fit of a mask is an important factor to minimize the contaminated region.