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Updated: Nov 1, 2025

Effects of Surgical Masks on Cardiopulmonary Function in Healthy Subjects
Published on: February 12, 2021
Effectiveness of different types of mask in aerosol dispersion in SARS-CoV-2 infection
Gokhan Tanisali1, Ahmet Sozak2, Abdul Samet Bulut2
1Department of Material Science and Engineering, Koç University, Istanbul, Turkey; Department of Molecular Biology and Genetics, Koç University, Istanbul, Turkey.
Objective:
To compare the effectiveness of different mask types in limiting the dispersal of coughed air.
Method:
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.
Results:
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.
Conclusions:
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.
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