Double masking protection vs. comfort-A quantitative assessment

Area of Science:

• Public Health
• Epidemiology
• Respiratory Medicine

Background:

• The COVID-19 pandemic necessitates effective source control measures like face masks.
• Mutations in SARS-CoV-2 (e.g., B.1.1.7, B.1.617) have increased transmissibility and mortality.
• Double masking is recommended by health experts to enhance protection against airborne virus transmission.

Purpose of the Study:

• To quantitatively assess the effectiveness of single and double mask configurations.
• To evaluate droplet leakage reduction with various mask combinations.
• To compare the efficacy of surgical, cotton, and N-95 masks in preventing virus transmission.

Main Methods:

• Systematic quantitative unsteady pressure measurements were employed.
• Flow visualization techniques were used to observe droplet leakage.
• Evaluated single masks, surgical + cotton double masks, and surgical + N-95 double masks.

Main Results:

• Tying a knot in surgical masks significantly improved fitment and reduced droplet leakage.
• A two-layer cotton mask over a surgical mask with a knot substantially decreased leakage.
• Surgical + N-95 and cotton + N-95 double masks showed no forward droplet leakage.
• Cotton + N-95 masks demonstrated the greatest reduction in mean (54.6%) and peak (23%) pressures compared to other combinations.

Conclusions:

• Double masking significantly enhances protection against COVID-19 variants.
• The combination of cotton and N-95 masks offers optimal protection and wearer comfort.
• Proper mask fitment, such as knotting surgical masks, is crucial for minimizing droplet leakage.